Blackboard Infectious Diseases EMQs Flashcards

1
Q

A 16 year old woman presents with a headache, fever and photophobia. Her mother became seriously concerned when she noticed a rash. O/E the girl grimaces with pain upon forced extension of the knee whilst her hip is flexed. You also demonstrate neck stiffness.

What is the diagnosis?
A.	Salmonella typhi
B.	Escherchia coliform
C.	Mycobacterium leprae
D.	Campylobacter jejuni
E.	Legionella pneumophila
F.	Neisseria meningitidis
G.	Pseudomonas aeroginosa
H.	Mycobacterium tuberculosis
A

F. Neisseria meningitidis

This patient has meningitis. Schools and universities are common sites of outbreaks due to crowding. Commonly there will be a headache, fever and nuchal rigidity. There may also be an altered mental status, confusion, photophobia and vomiting. Kernig’s sign is uncommon but is positive when attempts to extend the leg are met with resistance when the patient is supine with the thigh flexed to 90 degrees. Another uncommon sign is Brudzinski’s sign and a petechial/purpuric rash, typically associated with meningococcal meningitis.

CT head should be considered before LP if there is any evidence of raised ICP. An LP will confirm the diagnosis with bacterial meningitis showing a low CSF glucose, elevated CSF protein and positive CSF culture/gram stain or meningococcal antigen.

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2
Q

Miss A who recently moved to the UK from Ethiopia where she had undergone two months of antibiotic therapy for a cough, night sweats and blood stained sputum arrives at clinic with lower back pain and kyphosis. There is also hip pain.

What is the diagnosis?
A.	Salmonella typhi
B.	Escherchia coliform
C.	Mycobacterium leprae
D.	Campylobacter jejuni
E.	Legionella pneumophila
F.	Neisseria meningitidis
G.	Pseudomonas aeroginosa
H.	Mycobacterium tuberculosis
A

H. Mycobacterium tuberculosis

This patient has had pulmonary TB in Ethiopa but has not undergone a full course of anti-TB treatment. Subsequently, she has now developed extrapulmonary involvement. There is skeletal TB here with pain of the lower back. The onset of pain is usually gradual occuring over weeks to months and diagnosis is therefore frequently delayed. Local swelling and limitation of movement may be present, along with cold abscesses which may form if this is untreated. They are called cold abscesses as they are neither tender nor erythematous. These are also more common in HIV positive patients. MRI or a CT scan of the involved area is indicated here. Vertebral disease usually starts in the subchondral cancellous bone where it then spreads into the cortex and on to the disc. Destruction is more extensive on the ventral aspect than the dorsal aspect which leads to anterior wedging. As a result patients may present with kyphosis. There may also still be abnormalities on CXR consistent with TB. Note that normally TB initial therapy is a 4 drug regimen of isoniazid, rifampicin, pyrazinamide and ethambutol lasting for at least 6 months.

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3
Q

Three weeks following an illness which caused crampy abdominal pains, vomiting and diarrhoea a 26 year old presented with progressive bilateral leg weakness. Knee jerks and ankle jerks were both reduced on examination.

What is the diagnosis?
A.	Salmonella typhi
B.	Escherchia coliform
C.	Mycobacterium leprae
D.	Campylobacter jejuni
E.	Legionella pneumophila
F.	Neisseria meningitidis
G.	Pseudomonas aeroginosa
H.	Mycobacterium tuberculosis
A

D. Campylobacter jejuni

This patient has Guillain-Barre syndrome. This condition is a demyelinating polyneuropathy. Classic neurology is a progressive symmetrical muscle weakness affecting lower extremities before upper extremities, and proximal muscles before distal muscles, accompanied by paraesthesias in the hands and feet which often precedes onset of weakness. The paralysis is typically flaccid with areflexia and progresses acutely over days, with an ensuing plateau phase followed by recovery. Two thirds of patients have a history of either prior influenza-like illness or gastroenteritis. This patient gives a history of gastroenteritis, the cause of which is likely Campylobacter. Studies have shown that 60-70% of acute cases are preceded by Campylobacter jejuni infection. Additionally, Campylobacter-associated GBS appears to have a worse prognosis with slower recovery and higher residual neurological disability. A study in Sweden has shown that the risk of developing GBS after Campylobacter jejuni infection is roughly 100 fold higher than after other infections.

Other weak risks include immunisation, cancer and lymphoma, older age, HIV infection and male gender. Up to 30% will develop respiratory muscle weakness requiring ventilation so spirometry should be carried out at 6 hour intervals initially (and may show reduced vital capacity). AST and ALT may be elevated though the cause is unclear. LP is useful and the classic finding is of elevated CSF protein with normal cell count (known as albuminocytological dissociation). Treatment is with supportive and disease modifying treatment (plasma exchange or high dose Ig).

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4
Q

A 42 year old previously healthy plumber is brought to hospital very confused by his wife with a fever, bradycardia and SOB. Investigations reveal elevated WBC count and Na 127mmol/l, K 4.2mmol/l, urea 6.5mmol/l. The doctor orders a urine sample.

What is the diagnosis?
A.	Salmonella typhi
B.	Escherchia coliform
C.	Mycobacterium leprae
D.	Campylobacter jejuni
E.	Legionella pneumophila
F.	Neisseria meningitidis
G.	Pseudomonas aeroginosa
H.	Mycobacterium tuberculosis
A

E. Legionells pneumophilia

Legionella is a gram negative rod. Legionella infecting the lungs is legionnaires’ disease or Legionella pneumonia whereas non-lung infection is known as Pontiac fever. This bacteria is found in aqueous environments such as lakes and almost all cases are from contaminated water systems, which relates to the risk factors of getting Legionella (this patient is a plumber). Smoking is also a risk factor. It can cause confusion as well as hyponatraemia, abdominal pain, diarrhoea and bradycardia. Legionella does not grow on routine culture media and diagnosis relies on urine antigen detection (hence the request for a urine sample), serology or culture on special media.

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5
Q

Mr D is a 17 year old man with cystic fibrosis for which he receives intensive physiotherapy. He has come in with shortness of breath and a mild fever. Sputum cultures demonstrated the growth of an organism which also produced a green pigment.

What is the diagnosis?
A.	Salmonella typhi
B.	Escherchia coliform
C.	Mycobacterium leprae
D.	Campylobacter jejuni
E.	Legionella pneumophila
F.	Neisseria meningitidis
G.	Pseudomonas aeroginosa
H.	Mycobacterium tuberculosis
A

G. Pseudomonas aeroginosa

The green pigment here is pyoverdine which is produced by Pseudomonas. Pseudomonas has virulence factors for lung colonisation and is noted for its type III injection apparatus, which you may remember from your microbiology lectures. It is a gram negative bacilli causing hospital acquired pneumonia and UTI. It particularly affects immunocompromised hosts such as those on chemotherapy, those with cystic fibrosis (this patient), burns and wounds. Biofilms are antibiotic resistant.

Pseudomonas is also a special organism which is not sensitive to many antibiotics originally used for gram negatives. You need to prescribe a drug here which has specific anti-pseudomonal activity such as ceftazidime (a third generation cephalosporin), tazocin, ciprofloxacin, imipenem or gentamicin (usually used with one of the others). This organism acquires resistance genes very quickly so two antibiotics are given. It is, as mentioned, inherently resistant to many drug classes. Some are even resistant to all antibiotics.

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6
Q

Match the following organisms with the disease that they cause:

Mycobacterium tuberculosis

A.	Milroy's Syndrome
B.	Enteric fever
C.	Cat-scratch disease
D.	Chagas disease
E.	Wolf-Parkinson-White Syndrome
F.	Pseudomembranous colitis
G.	Pontiac fever
H.	Lyme disease
I.	Glandular fever
J.	Blackwater fever
K.	Pott’s disease
L.	Leprosy
A

K. Pott’s disease

Pott’s disease is a presentation of extrapulmonary TB which affects the spine. Vertebral disease usually starts in the subchondral cancellous bone where it then spreads into the cortex and on to the disc. Destruction is more extensive on the ventral aspect than the dorsal aspect which leads to anterior wedging. As a result Pott’s disease may present with kyphosis. There may also obviously be focal tenderness. MRI or CT needs to be obtained here and microbiological confirmation of TB is also essential. Note that paraspinous collections may also develop.

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7
Q

Match the following organisms with the disease that they cause:

Plasmodium falciparum

A.	Milroy's Syndrome
B.	Enteric fever
C.	Cat-scratch disease
D.	Chagas disease
E.	Wolf-Parkinson-White Syndrome
F.	Pseudomembranous colitis
G.	Pontiac fever
H.	Lyme disease
I.	Glandular fever
J.	Blackwater fever
K.	Pott’s disease
L.	Leprosy
A

J. Blackwater fever

Blackwater fever is a complication of malaria infection caused by haemolysis, which releases haemoglobin into the bloodstream. This passes into the urine and it is the presence of haemoglobinuria which defines this condition (seen with dark red or black urine, hence the name). It can often lead to renal failure.

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8
Q

Match the following organisms with the disease that they cause:

Clostridium difficile

A.	Milroy's Syndrome
B.	Enteric fever
C.	Cat-scratch disease
D.	Chagas disease
E.	Wolf-Parkinson-White Syndrome
F.	Pseudomembranous colitis
G.	Pontiac fever
H.	Lyme disease
I.	Glandular fever
J.	Blackwater fever
K.	Pott’s disease
L.	Leprosy
A

F. Pseudomembranous colitis

Pseudomembranous colitis is caused by clostridium difficile infection (occuring often after broad spectrum antibiotics). C. difficile produces 2 exotoxins which are responsible for its pathogenicity. These are called toxin A and toxin B (A is thought to be more important than B) which lead to an inflammatory response in the large bowel, increased vascular permeability and the formation of pseudomembranes. Colonic pseudomembranes look like raised yellow and white plaques against an inflamed mucosa and are composed of neutrophils, fibrin, mucin and cellular debris. The diagnostic standard is with cytotoxic tissue culture assay.

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9
Q

Match the following organisms with the disease that they cause:

Borrelia bugdorferi

A.	Milroy's Syndrome
B.	Enteric fever
C.	Cat-scratch disease
D.	Chagas disease
E.	Wolf-Parkinson-White Syndrome
F.	Pseudomembranous colitis
G.	Pontiac fever
H.	Lyme disease
I.	Glandular fever
J.	Blackwater fever
K.	Pott’s disease
L.	Leprosy
A

H. Lyme disease

Lyme disease is a tick-borne infection which is caused by a spirochete, Borrelia burgdorferi. This is not the only species of the genus Borrelia which can cause lyme disease but is the cause in the United States, which seems to have a rather large influence on literature (and spelling). In Europe, the cause is B afzelii, B garinii and B burgdorferi sensu stricto and in Asia it is primarily the first two mentioned. The major reservoirs for Borrelia are mice, voles, squirrels and other small animals. Deers are actually not a major reservoir of Borrelia but are often mentioned in EMQs because they are a major host for the adult ticks (Ixodes) which are the vectors of transmission. The most common initial manifestation is a characteristic skin lesion known as erythema migrans – later manifestations include arthritis, CNS or cardiac involvement. The mainstay of treatment is with antibiotics.

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10
Q

Match the following organisms with the disease that they cause:

Salmonella enterica

A.	Milroy's Syndrome
B.	Enteric fever
C.	Cat-scratch disease
D.	Chagas disease
E.	Wolf-Parkinson-White Syndrome
F.	Pseudomembranous colitis
G.	Pontiac fever
H.	Lyme disease
I.	Glandular fever
J.	Blackwater fever
K.	Pott’s disease
L.	Leprosy
A

H. Enteric fever

Enteric fever is also known as typhoid. It is a faecal-oral transmissible disease caused by Salmonella enterica and in the developed world, is mainly seen in travellers who have returned from endemic countries. The highest incidence is from the Indian sub-continent so this is always something to be aware of in EMQs. Note that typhoid vaccine offers no protection against paratyphoid infection. A blood culture would be diagnostic in this condition and antibiotic treatment would depend, or should depend, on the country of origin.

Look up the other conditions if you do not know what they are. Or look them up anyway – you will always be able to learn something new or recall something which you would otherwise have forgotten.

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11
Q

A twenty-one year old girl who presents with shortness of breath on climbing stairs, her boyfriend has told her that she looks very pale and should see the doctor.

What is the most appropriate investigation?
A.	CRP
B.	LP
C.	Sputum sample
D.	CXR and sputum sample
E.	LFTs
F.	Urinalysis
G.	FBC
H.	CT head
I.	Wound swab and culture
J.	Blood culture
K.	Pleural biopsy
L.	HIV test
A

G. FBC

Pallor and exertional SOB are suggestive of anaemia here. A FBC should be done here which would expect to find a low Hb. The World Health Organisation defines anaemia as <13g/dL in men older than 15, <12g/dL in non-pregnant women wolder than 15 and <11g/dL in pregnant women. This is likely to be iron deficiency anaemia so things to enquire in the history include diet, which could reveal a vegan diet. 40% of vegans aged 19-50 are iron deficient and this could also be comparable with levels in those who are vegetarians. Note also that iron absorption is enhanced by vitamin C whereas it is inhibited by tea and wine as well as calcium contained in dairy products. It is also worth enquiring about menstrual losses – menstrual iron loss is inversely related to iron status measured by ferritin. In IDA you can expect elevated platelet count, low MCV, low MCH and MCHC, raised RDW, low serum iron, increased TIBC, low transferrin saturation and low serum ferritin – a level <12ng/mL is diagnostic of IDA. Initial treatment can include oral iron although the underlying cause does need to be addressed, whatever that may be.

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12
Q

An 18 year old history student who has just started at university for his studies develops a pounding headache and fever. The hall warden remarked that he shouted at her to turn the lights off and draw the curtains when she was called to see him. He was then reported as having a seizure. On arrival to A&E, a CT head scan is done.

What is the most appropriate investigation?
A.	CRP
B.	LP
C.	Sputum sample
D.	CXR and sputum sample
E.	LFTs
F.	Urinalysis
G.	FBC
H.	CT head
I.	Wound swab and culture
J.	Blood culture
K.	Pleural biopsy
L.	HIV test
A

B. LP

This patient has meningitis. Universities are common sites of outbreaks due to crowding. Commonly there will be a headache, fever and nuchal rigidity. There may also be an altered mental status, confusion, photophobia and vomiting. An LP will confirm the diagnosis with bacterial meningitis showing a low CSF glucose, elevated CSF protein and positive CSF culture/gram stain or meningococcal antigen. A CT head scan should be considered before LP if there is reason to suspect raised ICP such as focal neurology, seizures, papilloedema on fundoscopy or altered mental state. The seizure here would be an indication to do a CT scan before attempting LP.

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13
Q

Mr D is an eco warrior who has spent the last 6 months in India. He has come back very thin with a persistent cough which occasionally produces blood streaked sputum. He has never smoked cigarettes before as it is capitalist.

What is the most appropriate investigation?
A.	CRP
B.	LP
C.	Sputum sample
D.	CXR and sputum sample
E.	LFTs
F.	Urinalysis
G.	FBC
H.	CT head
I.	Wound swab and culture
J.	Blood culture
K.	Pleural biopsy
L.	HIV test
A

D. CXR and sputum sample

This sounds like pulmonary TB although it could well also be bronchial carcinoma. Remember that adenocarcinomas are usually located peripherally in the lung and are more common in non-smokers although most cases are still associated with smoking. Which ever the diagnosis is, a CXR will be useful with a sputum sample being obtained to check for TB. This patient should be placed in isolation due to suspected TB and 3 sputum samples cultured for AFB being the gold standard for diagnosis. Culture takes several weeks so sputum smears will be done before culture results are known. Interferon-gamma release assays (IGRAs) are now used by some hospitals to rapidly determine a patient’s TB status. All patients who have TB should be tested for HIV within 2 months of diagnosis.

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14
Q

After coming out of surgery two weeks ago Mrs J’s arm wound has started to produce pus and the whole area is inflamed and red. She has come to you as she is concerned it is not healing.

What is the most appropriate investigation?
A.	CRP
B.	LP
C.	Sputum sample
D.	CXR and sputum sample
E.	LFTs
F.	Urinalysis
G.	FBC
H.	CT head
I.	Wound swab and culture
J.	Blood culture
K.	Pleural biopsy
L.	HIV test
A

I. Wound swab and culture

This is a straightforward question. A wound swab and culture is needed to see what the infection is. This will guide treatment.

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15
Q

Mrs M presents with a severe headache and fever for the past 3 days. Examination reveals fever, photophobia and neck stiffness. Fundoscopy is performed which reveals bilateral papilloedema.

What is the most appropriate investigation?
A.	CRP
B.	LP
C.	Sputum sample
D.	CXR and sputum sample
E.	LFTs
F.	Urinalysis
G.	FBC
H.	CT head
I.	Wound swab and culture
J.	Blood culture
K.	Pleural biopsy
L.	HIV test
A

H. CT head

This patient obviously has meningitis. A CT head scan needs to be done here before a diagnostic LP as there is reason to suspect raised ICP with bilateral papilloedema on fundoscopy. This can exclude a brain abscess or generalised cerebral oedema. Meningitis associated complications may also be identified such as hydrocephalus and brain infarction.

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16
Q

A young adult with a 2 day history of left sided pleuritic chest pain, fever and cough productive of rusty coloured sputum. A CXR was obtained which showed left lower lobe shadowing suggestive of consolidation. On agar the sputum grew gram +ve cocci which demonstrated alpha-haemolysis.

What is the diagnosis?
A.	Enterococcus faecium
B.	Shigella
C.	Chlamydia trachomatis
D.	Escherichia coli
E.	Salmonella typhi
F.	Chlamydophila psittaci
G.	Salmonella paratyphi
H.	Salmonella typhimurium
I.	Streptococcus pneumoniae
J.	Klebsiella pneumoniae
K.	Streptoccocus viridans
L.	Streptoccus pyogenes
A

I. Streptococcus pneumoniae

Classic lobar pneumonia with no signs and symptoms to suggest an atypical organism is most likely to due to pneumococcus. Streptococcus pneumoniae is, as mentioned in the question, an alpha haemolytic Gram positive cocci (also Streptococcus viridans but it does not present in this way). A CXR is the most specific and sensitive test available and antibiotics are indicated. The rusty coloured sputum is hinting at a pneumococcal pneumonia too.The patient has presented with common symptoms of fever and a productive cough. There is additionally pleuritic chest pain. Initial treatment of a CAP is empirical with antibiotics. Often diagnosis is made solely on history and examination findings. Management is guided by the patient’s CURB-65 score.

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17
Q

An infant (4 years old) who has a fever and rigors, who on examination has generalized lymphadenopathy is in the A+E. You can see an erythematous rash with desqamation on the hands and your registrar asks you to look at her tongue to look for another sign

What is the diagnosis?
A.	Enterococcus faecium
B.	Shigella
C.	Chlamydia trachomatis
D.	Escherichia coli
E.	Salmonella typhi
F.	Chlamydophila psittaci
G.	Salmonella paratyphi
H.	Salmonella typhimurium
I.	Streptococcus pneumoniae
J.	Klebsiella pneumoniae
K.	Streptoccocus viridans
L.	Streptoccus pyogenes
A

L. Streptococcus pyogenes

You are being asked here to look at the ‘strawberry’ tongue, or a red swollen tongue, which is a sign of Scarlet fever (along with Kawasaki disease and toxic shock syndrome which is caused by bacteria such as staphylococcus aureus). Scarlet fever is caused by an exotoxin released by Streptococcus pyogenes. The history is characteristically a child <10 years old, usually in the autumn, winter seasons, maybe early spring, presenting with sore throat, fever, malaise and GI upset. Examination may reveal a fever, pharyngeal redness with possible exudate, a generalised sandpaper-like erythematous rash, linear petechial streaks (pastia lines) in skin folds and tender cervical lymphadenopathy. The rash is characteristic in nature and blanches on pressure, appearing 12-72 hours after fever onset. When the rash begins to fade, desquamation begins, which can occur in the fingers. You can request a pharyngeal swab but the diagnosis is generally clinical. You can also expect ASO titres, if done, to be positive.

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18
Q

These organisms are an increasing problem as nosocomial infections. They are commensals of the gastrointestinal tract. Many are of these are vancomycin resistant.

What is the diagnosis?
A.	Enterococcus faecium
B.	Shigella
C.	Chlamydia trachomatis
D.	Escherichia coli
E.	Salmonella typhi
F.	Chlamydophila psittaci
G.	Salmonella paratyphi
H.	Salmonella typhimurium
I.	Streptococcus pneumoniae
J.	Klebsiella pneumoniae
K.	Streptoccocus viridans
L.	Streptoccus pyogenes
A

A. Enterococcus faecium

VRE stands for vancomycin resistent enterococci – most of these are Enterococcus faecium. Make sure you know the difference between Enterococcus faecalis and Enterococcus faecium. Most Enterococcus faecalis are not VRE but they are more prevalent than Enterococcus faecium. These are one of the big causes of nosocomial infections in the UK – these infections are defined as arising after 48 hours of hospital admission. Enterococcus faecium is Gram positive bacteria and is a commensal of the gastrointestinal tract. It is commonly implicated in hospital acquired line and urinary tract infection. The UK big 5 hospital-acquired infections at the moment are: MRSA, VRE, ESBL (E. coli and Klebsiella), Pseudomonas and Acinetobacter.

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19
Q

A whole family wake up in the early hours of the morning and rush for the toilet. They feel terrible and all blame their grandmother’s mousse from last nights dinner. Salmonella is cultured from stool samples.

What is the diagnosis?
A.	Enterococcus faecium
B.	Shigella
C.	Chlamydia trachomatis
D.	Escherichia coli
E.	Salmonella typhi
F.	Chlamydophila psittaci
G.	Salmonella paratyphi
H.	Salmonella typhimurium
I.	Streptococcus pneumoniae
J.	Klebsiella pneumoniae
K.	Streptoccocus viridans
L.	Streptoccus pyogenes
A

H. Salmonella typhimurium

This is salmonellosis. Non-typhoidal salmonella infection is caused by an organism in the genus Salmonella which is not Salmonella typhi. The most common one in the UK is actually Salmonella enteritidis. The most common ones identified in the United States, in order, are Salmonella typhimurium, Salmonella enteritidis and Salmonella newport. This is a very common cause of gastroenteritis in the developed world and can cause both sporadic cases and outbreaks of disease. Mousse is made from raw eggs and this is a risk factor. Cases are most commonly due to poultry or dairy items such as raw milk and undercooked eggs. More recently there have been outbreaks associated with peanut products and watermelons. Reptile exposure has also been associated with this disease. The presentation tends to be a self-limiting gastroenteritis – diagnosed based on isolation of the organism from stool cultures. Treatment is supportive with fluid and electrolyte replacement, with antibiotics withheld unless the patient has a risk of developing more severe disease or extraintestinal complications.

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20
Q

Teddy, 19, has been playing the field. He has developed a burning sensation upon urination

What is the diagnosis?
A.	Enterococcus faecium
B.	Shigella
C.	Chlamydia trachomatis
D.	Escherichia coli
E.	Salmonella typhi
F.	Chlamydophila psittaci
G.	Salmonella paratyphi
H.	Salmonella typhimurium
I.	Streptococcus pneumoniae
J.	Klebsiella pneumoniae
K.	Streptoccocus viridans
L.	Streptoccus pyogenes
A

C. Chlamydia trachomatis

If you initially read the question as ‘playing in the field’ and looked at the question in a confused way – so did I. Maybe he was playing the field, in the field? Teddy has developed genital tract infection with the organism chlamydia trachomatis, the only sexually transmitted infection on the list of options. Remember that many infected individuals (approximately 85%) are asymptomatic but in men there may be a discharge from the penis which is classically clear to whitish in colour and may be visible on examination. Additionally there may be dysuria, scrotal pain with ascending infections which cause epididymitis and in more severe cases, fever, N&V and rarely signs of rectal infection. The scrotal area can be tender to touch and feels warm. If there is no visible discharge then pressure along the shaft of the penis may extract fluid from the base to the tip. Tests are going to have to be performed here on urine or urethral samples. Untreated patients are at risk of possible ascending infection and further complications, and also there is a risk of spreading the infection to sexual partners.

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21
Q

A note from the lecturer on which pathogens to learn

A

It would be incredibly useful to know a little something about Gram staining – especially for EMQ questions. Gram positive organisms stain a violet/blue colour through methyl violet and Lugol’s iodine. Gram negatives stain a pink-red colour with methyl red, as the first stain which Gram positives retain is decolourised with acetone. Remember also that Mycobacteria stain poorly with Gram stain (use ZN stain instead), Mycoplasma has no cell wall, and organisms such as Rickettsia and Chlamydia are obligate intracellular organisms. I think the ones to know at this stage are:

Gram positive cocci: Streptococcus, Staphylococcus, Enterococcus
Gram positive bacilli: Clostridium, Listeria
Gram negative cocci: Neisseria, Haemophilus
Gram negative bacilli: Most EMQ bacteria not already mentioned (Salmonella, Shigella, Pseudomonas, Legionella, Vibrio, ESBL, Proteus…)

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22
Q

A 45 year old woman from Jamaica presents with a 6 month history of weight loss and a two week history of fever. On examination she had cervical lymphadenopathy. Her calcium was raised at 3.0 and CXR showed bilateral hilar lymphadenopathy.

What is the diagnosis?
A.	Influenza
B.	Pneumonia
C.	Glandular fever
D.	Post immunisation
E.	Tuberculosis
F.	Hodgkin's lympoma
G.	Pyelonephritis
H.	Gastric carcinoma
I.	HIV infection
J.	Appendicitis
K.	Malaria
L.	Drug reaction
M.	Sarcoidosis
N.	SLE
A

M. Sarcoidosis

Sarcoidosis is a chronic multisystem disease with an unknown aetiology. Lymphadenopathy is a common presentation and nodes are enlarged but non-tender, typically involving the cervical and submandibular nodes. Although uncommon, the patient may present with unexplained modest weight loss (which is often mistaken for TB or lymphoma along with the abnormal CXR) and a low-grade fever. CXR will typically show bilateral hilar lymphadenopathy and CXR findings are used in the staging of disease. Additionally, serum calcium and ACE levels may be raised. A transbronchial biopsy is essential for diagnosis in most cases and shows the presence of non-caseating granulomas. Black people have a higher lifetime risk of sarcoidosis, as do those of Scandinavian origin. The mainstay of treatment for severe disease involves systemic corticosteroids. Skin manifestations include erythema nodosum which are tender erythematous nodules and lupus pernio presenting with indurated plaques with discoloration on the face.

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23
Q

A 25 year old man with a 3 day history of high temperatures, aching limbs and neck discomfort. Apart from temperatures of 39 degrees C and some mild conjunctivitis, examination was normal. Antibiotics were prescribed but had no effect.

What is the diagnosis?
A.	Influenza
B.	Pneumonia
C.	Glandular fever
D.	Post immunisation
E.	Tuberculosis
F.	Hodgkin's lympoma
G.	Pyelonephritis
H.	Gastric carcinoma
I.	HIV infection
J.	Appendicitis
K.	Malaria
L.	Drug reaction
M.	Sarcoidosis
N.	SLE
A

A. Influenza

This is an acute respiratory tract infection caused by seasonal viral influenza A or B, hence antibiotics would have no effect. It is characterised by respiratory symptoms including rhinorrhoea, cough, fever, chills, headache and myalgia. Recent upper respiratory tract infection has led to associated viral conjuncitivitis. The examination in this case is of course otherwise unremarkable. Antigenic change presents a challenge in creating new vaccines as there is no incremental protection from previous vaccinations. There have been 4 pandemics since 1918, the recent one being ‘swine flu’ in April 2009, caused by new gene rearrangement of human, avian and swine influenza.

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24
Q

A 50 year woman normally resident in the UK returned from visiting relatives in Pakistan. She described intermittent fevers with rigors, diarrhoea and severe headaches. She is mildly jaundiced.

What is the diagnosis?
A.	Influenza
B.	Pneumonia
C.	Glandular fever
D.	Post immunisation
E.	Tuberculosis
F.	Hodgkin's lympoma
G.	Pyelonephritis
H.	Gastric carcinoma
I.	HIV infection
J.	Appendicitis
K.	Malaria
L.	Drug reaction
M.	Sarcoidosis
N.	SLE
A

K. Malaria

In the Western world, almost all cases of malaria occurs in travellers so an adequate travel history is crucial or the diagnosis may be missed. Patients typically present with non-specific symptoms such as a fever, sweats, chills and myalgia. This can also include the diarrhoea which this patient is experiencing and headaches. The jaundice here suggests falciparum infection, which is always the cause in severe disease. This woman has just returned from an endemic area. Sometimes EMQs will describe patterns of fevers occuring at regular intervals of 48-72 hours associated with P. vivax, P. ovale and P. malariae infections but in most patients there is no specific pattern. Hepatosplenomegaly is a common presenting sign although not common at presentation in a first world setting. Thrombocytopenia is common with falciparum infection and a mild degree of anaemia is commonly seen. WCC can be high, low or normal.

The severity of malaria depends partly on the species and also on host immunity. Therefore those who live in endemic areas may develop minimal symptoms due to IgG antibody and cell-mediated immunity and physiological tolerance of parasitaemia. Pregnant women affected by P. falciparum are also susceptible to the complications of pregnancy due to placental parasite sequestration. Treatment of malaria in pregnancy must be managed with an ID specialist and should be treated with IV antimalarial therapy.

The test of choice is Giesma-stained thick and thin blood smears. Thick films sensitively detect parasites whereas thin films allow species identification and calculation of parasitaemia to guide treatment. Studies have shown that for P falciparum, the most effective treatment is artesunate which is more effective than quinine without the risk of cinchonism. Numerous studies such as the AQUAMAT study in The Lancet showing that quinine should no longer be the established treatment of choice.

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25
Q

A 22 year old man presented with a two week history of fever and drenching night sweats. He had experienced severe itching during this time. Examination was normal except for swollen supraclavicular lymph nodes. CXR showed a mediastinal mass.

What is the diagnosis?
A.	Influenza
B.	Pneumonia
C.	Glandular fever
D.	Post immunisation
E.	Tuberculosis
F.	Hodgkin's lympoma
G.	Pyelonephritis
H.	Gastric carcinoma
I.	HIV infection
J.	Appendicitis
K.	Malaria
L.	Drug reaction
M.	Sarcoidosis
N.	SLE
A

F. Hodgkin’s lymphoma

This is a case of lymphoma. Reed-Sternberg cells are binucleate cells characteristically seen in Hodgkin’s lymphoma. Hodgkin’s is localised to a single group of nodes (normally the cervical and/or supraclavicular) and extranodal involvement is rare. Mediastinal involvement is common. Spread is contiguous and B symptoms may be present such as a low grade fever, weight loss and night sweats. Pruritis may be found in approximately 10% of cases but has no prognostic significance. 50% of cases is associated with EBV infection and distribution is bimodal with peaks in young and old. There is classically pain in lymph nodes on alcohol consumption.

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26
Q

A 35 year old pregnant woman developed a temperature with chills and increased urinary frequency. She is tender in the right loin and has vomited. Dipstick urinalysis is positive for leukocytes, nitrites and blood.

What is the diagnosis?
A.	Influenza
B.	Pneumonia
C.	Glandular fever
D.	Post immunisation
E.	Tuberculosis
F.	Hodgkin's lympoma
G.	Pyelonephritis
H.	Gastric carcinoma
I.	HIV infection
J.	Appendicitis
K.	Malaria
L.	Drug reaction
M.	Sarcoidosis
N.	SLE
A

G. Pyelonephritis

Acute onset fever with chills, flank pain, vomiting and positive urine dipstick all point to the diagnosis of acute pyelonephritis. Urinalysis is highly sensitive but not very specific. Pregnancy is a risk factor for complicated disease as the enlarging uterus compresses the ureters and hormonal changes increase the likelihood of obstructive uropathy. In uncomplicated pyelonephritis, the most common cause is E. coli and gram stain will typically reveal gram negative rods, either E. coli, Proteus or Klebsiella. Gram positive cocci that could be implicated include enterococci and staphylococci. Older patients can often also present non-specifically. Treatment should start before culture results are received to prevent the patient from deteriorating, with empirical antibiotics.

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27
Q

A 50 year old woman presented with a temperature and aching joints 2 days prior to departure on holiday to Egypt. On examination she had a tender swelling on her left upper arm.

What is the diagnosis?
A.	Influenza
B.	Pneumonia
C.	Glandular fever
D.	Post immunisation
E.	Tuberculosis
F.	Hodgkin's lympoma
G.	Pyelonephritis
H.	Gastric carcinoma
I.	HIV infection
J.	Appendicitis
K.	Malaria
L.	Drug reaction
M.	Sarcoidosis
N.	SLE
A

D. Post immunisation

Travel to Egypt may necessitate vaccinations for diseases such as typhoid and HAV. This is a side-effect of the vaccine and the history here points towards this. Vaccine side effects tend to be uncommon although this depends on the specific vaccine given. For example, some 10-30% of people will experience mild side effects such as muscle pain and headache after being given the yellow fever vaccine.

28
Q

A 40 year old man returned from India 4 days ago & came down with fever. He went to his GP & got some paracetamol. His fever persisted, & he had a few bouts of diarrhoea & cough. He started getting drowsy & was admitted from casualty where his blood culture was taken. The next day the lab reported Gram negative bacilli seen on blood culture.

What is the diagnosis?
A.	Falciparum malaria
B.	Dengue virus
C.	Neisseria meningitidis type B
D.	Streptococcus pneumoniae
E.	Entomoeba histolytica
F.	Mycobacterium tuberculosis
G.	Influenza
H.	Salmonella typhi
I.	Lassa fever
J.	Legionella pneumophila
A

H. Salmonella typhi

Typhoid (or enteric fever) is a faecal-oral illness caused by Salmonella enterica, serotype S typhi, Salmonella enterica and S paratyphi. There are over 2500 serovars for S enterica. In this country, it is mainly from people who have returned from a country where it is endemic – India, for example, which has the highest incidence of this disease. Mexico should also ring alarm bells. The water supplies are not treated and sanitary conditions are dire which prompts transmission of this infection. Humans are the only known reservoir. The vaccine only offers moderate protection and does not protect against paratyphoid infection. This person has a high fever which is a hallmark of infection (sometimes in a step-wise manner) which is not responding to paracetamol (it persists) and blood culture (you need a big sample of blood for testing as count is usually low) shows a gram negative bacilli, and he has returned from an endemic region. The fever of typhoid classically increases incrementally until a persistent fever with temperature 39-41 is established. There are also typically flu like symptoms after onset of fever and cough. Remember that characteristic findings such as bradycardia and rose spots may not be present and indeed rose spots may not be easy to spot in those with dark skin. Rose spots are blanching red lesions reported in 5-30% of cases usually occuring on the chest or abdomen.

This patient needs antibiotics though the temperature will fall over about week. A third generation cephalosporin is indicated due to resistance to fluoroquinolones in the Indian sub-continent. If the sensitivity panel returns and shows that this organism is sensitive to all antibiotics then ciprofloxacin should be given.

29
Q

50 year old man went for Hajj. He was vaccinated against hepatitis & Group C meningococci. He came back with a high fever & was admitted with neck stiffness & drowsiness. He had a lumbar puncture & blood cultures. Gram stain of cerebrospinal fluid showed Gram negative diplococci.

What is the diagnosis?
A.	Falciparum malaria
B.	Dengue virus
C.	Neisseria meningitidis type B
D.	Streptococcus pneumoniae
E.	Entomoeba histolytica
F.	Mycobacterium tuberculosis
G.	Influenza
H.	Salmonella typhi
I.	Lassa fever
J.	Legionella pneumophila
A

C. Neisseria meningitidis type B

This patient has meningitis. A big risk factor is crowding which occurs during Hajj. Commonly there will be a headache, fever and nuchal rigidity. There may also be an altered mental status, confusion, photophobia and vomiting. Kernig’s sign is uncommon but is positive when attempts to extend the leg are met with resistance when the patient is supine with the thigh flexed to 90 degrees. Another uncommon sign is Brudzinski’s sign and a petechial/purpuric rash, typically associated with meningococcal meningitis.

CT head should be considered before LP if there is any evidence of raised ICP. A LP will confirm the diagnosis with bacterial meningitis showing a low CSF glucose, elevated CSF protein and positive CSF culture/gram stain or meningococcal antigen. The CSF gram stain showing a gram negative diplococci here gives the organism away. If you know your gram stains etc you can get this one from just reading the last line.

30
Q

40 year old social worker, lived in India & the Far East for the last 2 years. He came back with an intermittent fever of 2 months duration. On examination the GP noted tenderness & swelling of the right hypochondrium. He was sent to the hospital where on ultrasound a liver abscess was found.

What is the diagnosis?
A.	Falciparum malaria
B.	Dengue virus
C.	Neisseria meningitidis type B
D.	Streptococcus pneumoniae
E.	Entomoeba histolytica
F.	Mycobacterium tuberculosis
G.	Influenza
H.	Salmonella typhi
I.	Lassa fever
J.	Legionella pneumophila
A

E. Entomoeba histolytica

This is amoebiasis caused by E. Histolytica. Again, there is history of travel to an endemic area. Additional risk factors include being male and male-male sex, both oral and anal. Diagnosis would be confirmed by the detection of antigen in stool samples, serology or PCR. As neither of these methods are 100% sensitive, it is normally good to use more than 1 test in diagnosis. The presentation is normally with diarrhoea, without blood or mucus, present for several days or longer, indicating intestinal infection. Half also report weight loss. This patient, has however got the fever more associated with hepatic infection. There may also be jaundice here and hepatomegaly on examination. The RUQ tenderness found here is indicative of hepatic infection and the mass here is likely a hepatic abscess, which itself may extend into the pleural or pericardial cavities in rare cases, causing effusions. Splenic abscesses and even brain abscesses with neurological abnormalities can also rarely occur. Treatment is with nitroimidazoles followed by agents like paromomycin.

31
Q

30 year old stone mason came from India to work on a temple being constructed. He presented to the GP with history of fever, night sweats & cough of 3 months duration. Chest x-ray showed a cavitating shadow.

What is the diagnosis?
A.	Falciparum malaria
B.	Dengue virus
C.	Neisseria meningitidis type B
D.	Streptococcus pneumoniae
E.	Entomoeba histolytica
F.	Mycobacterium tuberculosis
G.	Influenza
H.	Salmonella typhi
I.	Lassa fever
J.	Legionella pneumophila
A

F. Mycobacterium tuberculosis

It is important to have a high level of suspicion when evaluating patients with risk factors who present with suggestive symptoms. Night sweats, fever, malaise, cough, haemoptysis and erythema nodosum are all suggestive. In the first half of the 20th century, tuberculosis accounted for over 90% of cases of erythema nodosum. Other key risk factors for pulmonary TB include exposure to infection and returning from or being born in a high-risk region such as Asia, Africa and Latin America. If TB is suspected, the patient should be placed in isolation and a CXR obtained with 3 sputum samples cultured for AFB being the gold standard of diagnosis. Cavitating lesions like the one this patient has can be seen on CXR but is non-specific for TB. Culture takes several weeks so sputum smears will be done before culture results are known. Interferon-gamma release assays (IGRAs) are now used by some hospitals to rapidly determine a patient’s TB status. All patients who have TB should be tested for HIV within 2 months of diagnosis.

32
Q

A 22 year old female medical student returned from elective in Nigeria 3 months ago, she has had a fever & night sweats for 3 weeks.

What is the most appropriate investigation?
A.	Blood cultures
B.	IVP
C.	Liver function tests
D.	Throat swabs
E.	Full blood count
F.	Chest x-ray &amp; sputum cultures
G.	Abdominal ultrasound
H.	Urine microscopy &amp; culture
I.	CT brain scan
J.	Thick blood film
K.	Lumbar puncture
L.	Echocardiogram
M.	Clinical exam only
A

J. Thick blood film

In the Western world, almost all cases of malaria occurs in travellers so an adequate travel history is crucial or the diagnosis may be missed. Patients typically present with non-specific symptoms such as a fever, sweats, chills and myalgia. This medical student has just returned from an endemic area. Sometimes EMQs will describe patterns of fevers occuring at regular intervals of 48-72 hours associated with P. vivax, P. ovale and P. malariae infections but in most patients there is no specific pattern.

The test of choice is Giesma-stained thick and thin blood smears. Thick films sensitively detect parasites whereas thin films allow species identification and calculation of parasitaemia to guide treatment. Studies have shown that for P falciparum, the most effective treatment is artesunate which is more effective than quinine without the risk of cinchonism. However, not all hospitals are currently licensed to use it in the UK (in London, only the Hospital for Tropical Diseases and Northwick Park). Artesunate is manufactured by a pharmaceutical company in China and there are doubts over the quality of the product. However, there have now been numerous studies such as the AQUAMAT study in The Lancet showing that quinine should no longer be the established treatment of choice.

33
Q

A 23 year old man has been living rough in London since being made homeless 6 months ago. He presents in A&E, unwell with 1 month history of cough, weight loss, fever & night sweats.

What is the most appropriate investigation?
A.	Blood cultures
B.	IVP
C.	Liver function tests
D.	Throat swabs
E.	Full blood count
F.	Chest x-ray &amp; sputum cultures
G.	Abdominal ultrasound
H.	Urine microscopy &amp; culture
I.	CT brain scan
J.	Thick blood film
K.	Lumbar puncture
L.	Echocardiogram
M.	Clinical exam only
A

F. Chest x-ray & sputum cultures

The patient’s symptoms point towards pulmonary TB. CXR is the first line test to order. Classically, in primary disease there are middle and lower zone infiltrates. Post-primary TB usually involves apical changes with or without cavitation. However, recent students have indicated that both presentations are seen in both primary and post-primary TB. HIV positive patients tend to have a more atypical CXR including effusion, lower zone involvement and a miliary pattern. Sputum cultures on LJ medium are the most sensitive and specific test but growth on solid media can take 4-8 weeks. A smear will be done in the meantime to look for AFB but the sensitivity is lower than that of a culture.

34
Q

An 18 year old student started university 3 months ago. She has felt flu-like for 2 days. In the last 2 hours she has developed a severe headache, vomiting, temp of 390C & photophobia. On examination she has neck stiffness & a positive Kernig’s sign.

What is the most appropriate investigation?
A.	Blood cultures
B.	IVP
C.	Liver function tests
D.	Throat swabs
E.	Full blood count
F.	Chest x-ray &amp; sputum cultures
G.	Abdominal ultrasound
H.	Urine microscopy &amp; culture
I.	CT brain scan
J.	Thick blood film
K.	Lumbar puncture
L.	Echocardiogram
M.	Clinical exam only
A

K. Lumber puncture

This patient has meningitis. Universities are common sites of outbreaks due to crowding. Commonly there will be a headache, fever and nuchal rigidity. There may also be an altered mental status, confusion, photophobia and vomiting. Kernig’s sign is uncommon but is positive when attempts to extend the leg are met with resistance when the patient is supine with the thigh flexed to 90 degrees. Another uncommon sign is Brudzinski’s sign and a petechial/purpuric rash, typically associated with meningococcal meningitis.

CT head should be considered before LP if there is any evidence of raised ICP. A LP will confirm the diagnosis with bacterial meningitis showing a low CSF glucose, elevated CSF protein and positive CSF culture/gram stain or meningococcal antigen.

35
Q

5 days after a bowel resection for cancer, a 70 year old man gets a swinging fever & becomes confused.

What is the most appropriate investigation?
A.	Blood cultures
B.	IVP
C.	Liver function tests
D.	Throat swabs
E.	Full blood count
F.	Chest x-ray &amp; sputum cultures
G.	Abdominal ultrasound
H.	Urine microscopy &amp; culture
I.	CT brain scan
J.	Thick blood film
K.	Lumbar puncture
L.	Echocardiogram
M.	Clinical exam only
A

A. Blood cultures

Post-surgical patients are at risk of developing an abscess. An abscess is a collection of pus or infected material. A swinging fever is strongly indicative of an abscess and a blood culture is required to identify the pathogenic organism. Percutaneous or surgical drainage will usually be required with appropriate antimicrobial therapy.

36
Q

A 3 year old girl is febrile and has been unwell for 12 hours. She complains of a headache and is drowsy but otherwise neurologically intact.

What is the most appropriate investigation?
A.	ESR
B.	Urine culture
C.	Lumbar puncture
D.	Blood cultures
E.	EEG
F.	Culture of joint aspirate
G.	Stool electron microscopy
H.	Full blood count
I.	Stool culture
J.	CT brain
K.	Chest X-ray
L.	C-reactive protein
M.	Throat swab
A

C. Lumber puncture

Meningitis commonly affects the extremes of age (<5 years and >60 years) due to impaired immunity in the former, and waning immunity in the latter. A lumbar puncture to obtain CSF is the most important investigation when this diagnosis is considered. This should not however delay the starting of empirical antimicrobial therapy. When the specific organism is identified, treatment can be modified accordingly. Fever, headache and drowsiness should make you suspicious here of this diagnosis. Atypical presentations can also occur, and these tend to happen in the very young, older or immunocompromised patients. In older patients, frequently, the only presenting sign of meningitis is confusion or an altered mental status. In infants, the signs and symptoms can be very non-specific and may include lethargy, poor feeding, irritability and fever. A rash is noted in 80-90% of patients, commonly 4-18 hours after initial symptoms and is associated with meningococcal aetiology (although may be present with any bacterial meningitis).

In bacterial meningitis, the CSF pressure is usually raised and WBC count is elevated. The glucose level is decreased compared to the serum value and the protein level is increased. In those who are untreated, Gram stain and culture of CSF are usually positive for the causative organism. However, in those who get antibiotics before cultures are obtained, the diagnostic yield is much lower (as low as 20%). If a lumbar puncture is delayed or regarded as clinically unsafe (for instance, raised intracranial pressure), then blood samples should be obtained for culture. Of course, a head CT should be considered before LP if there is focal neurology, new onset seizures, papilloedema, altered consciousness or any sign which may indicate raised ICP.

37
Q

A 2 month old child has had a fever and cough for three days. He is tachypnoeic with grunting and has nasal flaring.

What is the most appropriate investigation?
A.	ESR
B.	Urine culture
C.	Lumbar puncture
D.	Blood cultures
E.	EEG
F.	Culture of joint aspirate
G.	Stool electron microscopy
H.	Full blood count
I.	Stool culture
J.	CT brain
K.	Chest X-ray
L.	C-reactive protein
M.	Throat swab
A

K. Chest X-ray

This 2 month old child has pneumonia and is displaying signs of respiratory distress (tachypnoea, nasal flaring, grunting). The most sensitive and specific test to perform is a CXR (PA and lateral). What may be seen is an infiltrate, consolidation, effusions and cavitation. Initial treatment is empirical with antibiotics (amoxicillin is the first choice in children).

38
Q

A 3 year old has had a high fever and sore throat for 2 days. This evening he had a generalised convulsion lasting 2 minutes. He is now drowsy but rousable with no localising signs.

What is the most appropriate investigation?
A.	ESR
B.	Urine culture
C.	Lumbar puncture
D.	Blood cultures
E.	EEG
F.	Culture of joint aspirate
G.	Stool electron microscopy
H.	Full blood count
I.	Stool culture
J.	CT brain
K.	Chest X-ray
L.	C-reactive protein
M.	Throat swab
A

M. Throat swab

This child has septicaemia secondary to a throat infection caused by group A beta-haemolytic streptococcus (Streptococcus pyogenes). This is no additional reason to believe that this is toxic shock syndrome or rheumatic fever, but the sore throat and fever for 2 weeks requires a culture of a throat swab to look for the causative organism. This is the most specific and sensitive test for GAS. However, a rapid antigen test can also be done for GAS which is about 80% sensitive and 95% specific compared to a throat culture but obviously much quicker. Blood cultures can also be done as the infection is now systemic but the throat culture is the best choice here as this is the obvious initial source of the infection. Treatment is with antibiotics and may be with penicillin or amoxicillin. GAS resistance to macrolides has been reported. Supportive care in this patient is also essential.

39
Q

An 8 year old has developed a painful, swollen knee over the last day. O/E there is a tender, warm effusion of the left knee. She also has a pyrexia of 38 degrees.

What is the most appropriate investigation?
A.	ESR
B.	Urine culture
C.	Lumbar puncture
D.	Blood cultures
E.	EEG
F.	Culture of joint aspirate
G.	Stool electron microscopy
H.	Full blood count
I.	Stool culture
J.	CT brain
K.	Chest X-ray
L.	C-reactive protein
M.	Throat swab
A

F. Culture of joint aspirate

This 8 year old has septic arthritis. The septic knee joint here will be painful, hot, swollen and restricted movement of the affected joint. In all cases of suspected joint sepsis, the joint needs to be aspirated and empirical antibiotics need to be commenced once appropriate cultures have been taken. If the cause is a low virulence organism, TB or if in an older patient, the joint is prosthetic, then the presentation may be more insidious in onset. If there is already underlying joint disease then a septic joint should be suspected if the symptoms are out of proportion to normal disease activity. Some 20% of cases of septic arthritis is polyarticular. In sexually active patients, gonococcal arthritis is an important differential to consider. Presence or absence of fever is not a reliable indicator of joint sepsis and the diagnosis is largely one of clinical suspicion – treatment should therefore be commenced on this basis regardless of blood test results or microbiology. Synovial fluid Gram stain and culture is however positive in 70% of cases.

40
Q

A 12 month old boy has a 24 hour history of profuse diarrhoea and irritability. He has a low grade fever.

What is the most appropriate investigation?
A.	ESR
B.	Urine culture
C.	Lumbar puncture
D.	Blood cultures
E.	EEG
F.	Culture of joint aspirate
G.	Stool electron microscopy
H.	Full blood count
I.	Stool culture
J.	CT brain
K.	Chest X-ray
L.	C-reactive protein
M.	Throat swab
A

I. Stool culture

The best investigation for presumed infectious diarrhoea here is to do a stool culture. It is not an absolutely necessary investigation in most cases as the mainstay of treatment is supportive with rehydration and the correction of electrolyte imbalance. However, stool cultures should be sent from patients with symptoms which are persistent or severe enough to prompt the patient to seek medical attention. Cultures are also mandatory in cases of bloody diarrhoea and signs of systemic involvement. The cultures should be sent within 3 days of admission as the yield is significantly reduced beyond this time period – and results take 2-4 days to become available.

This condition is more common in the extremes of age and complications are also more common in these groups. The commonly examined complication is haemolytic uraemic syndrome, which develops in 10% of patients with E coli O157 infection. Another complication is death, which is uncommonly examined but needless to say most patients who die from infectious diarrhoea are at the extremes of age. Diarrhoeal illness in young infants under 2 years of age is characteristically caused by EPEC (enteropathogenic E coli). Use of antibiotics is controversial and in most cases is not necessary (except possible in traveller’s diarrhoea).

41
Q

A 30 year old, man became unwell 4 weeks after a holiday in Africa. He developed headaches, muscle pains, feeling cold, severe rigors, high fever, flushing, vomiting and profuse sweating.

What is the diagnosis?
A.	HIV
B.	Enteric fever
C.	CMV (cytomegalovirus)
D.	Giardiasis
E.	Tetanus
F.	Viral hepatitis
G.	Syphilis
H.	Toxoplasmosis
I.	Influenza
J.	Malaria
K.	Glandular fever
L.	Polio
M.	Cholera
N.	Rabies
O.	Herpes zoster (shingles)
P.	Tuberculosis
A

J. Malaria

In the Western world, almost all cases of malaria occurs in travellers so an adequate travel history is crucial or the diagnosis may be missed. Malaria is endemic in many parts of Africa and this is a clue. Patients typically present with non-specific symptoms such as a fever, sweats, chills and myalgia. Sometimes EMQs will describe patterns of fevers occuring at regular intervals of 48-72 hours associated with P. vivax, P. ovale and P. malariae infections but in most patients there is no specific pattern. The test of choice is Giesma-stained thick and thin blood smears. Thick films sensitively detect parasites whereas thin films allow species identification and calculation of parasitaemia to guide treatment. Note that blackwater fever is a complication of malaria which occurs due to haemolysis and the release of haemoglobin into blood vessels and subsequently into the urine, which can frequently lead to renal failure.

42
Q

A 50 year old man became unwell after a holiday in India. He developed a fever, tiredness, night sweats and a productive cough. He lost half a stone in weight since his return from holiday 6 weeks ago.

What is the diagnosis?
A.	HIV
B.	Enteric fever
C.	CMV (cytomegalovirus)
D.	Giardiasis
E.	Tetanus
F.	Viral hepatitis
G.	Syphilis
H.	Toxoplasmosis
I.	Influenza
J.	Malaria
K.	Glandular fever
L.	Polio
M.	Cholera
N.	Rabies
O.	Herpes zoster (shingles)
P.	Tuberculosis
A

P. Tuberculosis

The patient’s symptoms and travel history point towards pulmonary TB. It is important to have a high level of suspicion when evaluating patients with risk factors who present with suggestive symptoms. Night sweats, fever, malaise, cough, haemoptysis and erythema nodosum are all suggestive. Key risk factors for pulmonary TB include exposure to infection and returning from or being born in a high-risk region such as Asia, Africa and Latin America. If TB is suspected, the patient should be placed in isolation and a CXR obtained with 3 sputum samples cultured for AFB being the gold standard of diagnosis. Culture on solid media can take 4-8 weeks so sputum smears will be done before culture results are known. Interferon-gamma release assays (IGRAs) are now used by some hospitals to rapidly determine a patient’s TB status. All patients who have TB should be tested for HIV within 2 months of diagnosis.

Classically, in primary disease CXR shows middle and lower zone infiltrates. Post-primary TB usually involves apical changes with or without cavitation. However, recent students have indicated that both presentations are seen in both primary and post-primary TB. HIV positive patients tend to have a more atypical CXR including effusion, lower zone involvement and a miliary pattern.

43
Q

A 20 year old student presented with a sore throat, fever, anorexia, malaise and lymphadenopathy. She was treated for tonsillitis by her GP but did not complete the course because she developed an allergic rash.

What is the diagnosis?
A.	HIV
B.	Enteric fever
C.	CMV (cytomegalovirus)
D.	Giardiasis
E.	Tetanus
F.	Viral hepatitis
G.	Syphilis
H.	Toxoplasmosis
I.	Influenza
J.	Malaria
K.	Glandular fever
L.	Polio
M.	Cholera
N.	Rabies
O.	Herpes zoster (shingles)
P.	Tuberculosis
A

K. Glandular fever

EBV causes a maculopapular pattern after ampicillin, which is what this patient has been given. Infectious mononucleosis (glandular fever) is caused by EBV and is characterised by fever, pharyngitis and lymphadenopathy. Enlargement of the spleen also begins in the first week and lasts 3-4 weeks, occuring in half of all cases. Risk factors for EBV transmission include kissing and sex (your 20 year old student here). A FBC will show an atypical lymphocytosis. Confirmation of IM involves detection of the existence of heterophile antibodies using the Paul Bunnell monospot. A more accurate test is a serological test detecting EBV specific antibodies. Treatment is usually symptomatic but IM carries rare but potentially life threatening complications.

44
Q

A 60 year old diabetic man with fever, malaise, headache and muscle pains. After a few days he became very ill and is now confined to his bed with a hot water bottle.

What is the diagnosis?
A.	HIV
B.	Enteric fever
C.	CMV (cytomegalovirus)
D.	Giardiasis
E.	Tetanus
F.	Viral hepatitis
G.	Syphilis
H.	Toxoplasmosis
I.	Influenza
J.	Malaria
K.	Glandular fever
L.	Polio
M.	Cholera
N.	Rabies
O.	Herpes zoster (shingles)
P.	Tuberculosis
A

I. influenza

Diabetics are more suspectible to infectious such as flu. This is an acute respiratory tract infection caused by seasonal viral influenza A or B, hence antibiotics would have no effect. It is characterised by respiratory symptoms including rhinorrhoea, cough, fever, chills, headache and myalgia. Examination can be expected to be otherwise unremarkable. Antigenic change presents a challenge in creating new vaccines as there is no incremental protection from previous vaccinations. There have been 4 pandemics since 1918, the recent one being ‘swine flu’ in April 2009, caused by new gene rearrangement of human, avian and swine influenza.

45
Q

Two weeks after a holiday in the Far East, a 30 year old lady presented with anorexia, fever and joint pains. Jaundice appeared a week later and on examination her liver and spleen were both enlarged and very tender.

What is the diagnosis?
A.	HIV
B.	Enteric fever
C.	CMV (cytomegalovirus)
D.	Giardiasis
E.	Tetanus
F.	Viral hepatitis
G.	Syphilis
H.	Toxoplasmosis
I.	Influenza
J.	Malaria
K.	Glandular fever
L.	Polio
M.	Cholera
N.	Rabies
O.	Herpes zoster (shingles)
P.	Tuberculosis
A

F. Viral hepatitis

This is likely hepatitis A which is primarily transmitted via the faecal-oral route. After the virus is consumed and absorbed, it replicates in the liver and is excreted in the bile (to be re-transmitted). Transmission usually precedes symptoms by about 2 weeks and patients are non-infectious one week after onset of jaundice. The history can reveal risk factors such as living in an endemic area, contact with an infected person, homosexual sex or a known food-borne outbreak. This is classically, in EMQs, associated with shellfish which is harvested from sewage contaminated water.

The clinical course of HAV consists of a pre-icteric phase, lasting 5-7 days, consisting characteristically of N&V, abdominal pain, fever, malaise and headache. Rarer symptoms may be present such as arthralgias and even severe thrombocytopenia and signs that may be found include splenomegaly, RUQ tenderness and tender hepatomegaly as well as bradycardia. The icteric phase is characterised by dark urine, pale stools, jaundice and pruritis. When jaundice comes on, the pre-icteric phase symptoms usually diminish, and jaundice typically peaks at 2 weeks. However, a fulminant course runs in <1% of patients with worsenining jaundice and encephalopathy. Serum transaminases may reach in excess of 10,000 units, although there is little correlation between the level and disease severity. ALT is typically higher than AST.

46
Q

A 20 year old lady became ill 2 weeks after a holiday in Brazil. She developed a fever, headache, cough & constipation which turned to diarrhoea 10 days later. She also has a blanching red lesion on her chest and abdomen. She is also found to be bradycardic.

What is the diagnosis?
A.	HIV
B.	Enteric fever
C.	CMV (cytomegalovirus)
D.	Giardiasis
E.	Tetanus
F.	Viral hepatitis
G.	Syphilis
H.	Toxoplasmosis
I.	Influenza
J.	Malaria
K.	Glandular fever
L.	Polio
M.	Cholera
N.	Rabies
O.	Herpes zoster (shingles)
P.	Tuberculosis
A

B. Enteric fever

Typhoid (or enteric fever) is a faecal-oral illness caused by Salmonella enterica, serotype S typhi, Salmonella enterica and S paratyphi. There are over 2500 serovars for S enterica. In this country, it is mainly from people who have returned from a country where it is endemic. The water supplies in Brazil may not treated and sanitary conditions may be dire which prompts transmission of this infection. Humans are the only known reservoir. The vaccine only offers moderate protection and does not protect against paratyphoid infection. This person has a fever which is a hallmark of infection. The fever of typhoid classically increases incrementally until a persistent fever with temperature 39-41 is established. There are also typically flu like symptoms after onset of fever and cough. Remember that characteristic findings such as bradycardia and rose spots may not be present and indeed rose spots may not be easy to spot in those with dark skin. Rose spots are blanching red lesions reported in 5-30% of cases usually occuring on the chest or abdomen.

This patient needs antibiotics though the temperature will fall over about week. A third generation cephalosporin is indicated. If the sensitivity panel returns and shows that this organism is sensitive to all antibiotics then ciprofloxacin should be given.

47
Q

A 40 year old business man travels frequently to the Far East and Africa. He became generally unwell with a fever, generalised lymphatic swelling, diarrhoea. On examination he was noted to have oral canididasis.

What is the diagnosis?
A.	Herpes Zooster (Shingles)
B.	Toxoplasmosis
C.	CMV (cytomegalovirus)
D.	Tetanus
E.	Malaria
F.	Cholera
G.	Syphilis
H.	Rabies
I.	Polio
J.	Influenza
K.	Tuberculosis
L.	Viral Hepatitis
M.	Giardiasis
N.	HIV
O.	Glandular Fever
A

N. HIV

The aim here is to establish the patient’s prognosis and begin the patient on HAART (highly active antiretroviral therapy). This patient needs to have a CD4 count, screen for HBV and HCV, VDRL, tuberculin skin test and a CXR. HIV viral load is also assessed at baseline. Generalised lymphadenopathy is common in HIV and present as painless enlarged nodes, usually in 2 or more non-contiguous sites, of >1cm for > 3months. Fevers and night sweats are also commonly seen, which may also indicate TB, which needs to be excluded (and malaria if from an endemic area). Unexplained diarrhoea of >1 month duration with no pathogen diagnosed is also seen in HIV. The oral candidiasis is also indicative of HIV and is an opportunitistic infection in an immunocompromised host. This patient has WHO stage 3 disease and would be placed in CDC category B, or symptomatic non-AIDS conditions. Oropharyngeal candidiasis is not AIDS indicating, but if this patient has candidiasis of the bronchi, trachea or lungs, or oesophagus then this would indicate an AIDS diagnosis (CDC category C – once the patient reaches category C, they stay in this category). I would not worry too much about clinical staging which is done according to the WHO or CDC criteria.

Other category C conditions, which indicate AIDS, include CMV retinitis, Kaposi’s sarcoma, Mycobacterium avium complex/tuberculosis/other, PCP and toxoplasmosis. Key risk factors for HIV include needle sharing with IVDU, unprotected homo- and heterosexual intercourse (a higher risk if the receptive partner, particular with receptive anal intercourse), HIV infected blood transfusion, needle stick injury and high maternal viral load (mother to child transmission).

48
Q

A 25 year old man developed a fever, malaise, lymphadenopathy and a rash on the palms of his soles of his feet. 6 weeks earlier he had a painless ulcer on his penis.

What is the diagnosis?
A.	Herpes Zooster (Shingles)
B.	Toxoplasmosis
C.	CMV (cytomegalovirus)
D.	Tetanus
E.	Malaria
F.	Cholera
G.	Syphilis
H.	Rabies
I.	Polio
J.	Influenza
K.	Tuberculosis
L.	Viral Hepatitis
M.	Giardiasis
N.	HIV
O.	Glandular Fever
A

G. Syphilis

Syphilis is a common STI which is caused by the spirochete bacterium Treponema pallidum (subspecies pallidum). This history is textbook syphilis. People at high risk include those who have had sexual contact with an infected person, men who have sex with men, those with HIV and other STDs, those with multiple partners, commercial sex workers and those who use illicit drugs. The presentation is often asymptomatic but can manifest in many different ways. There is a ulcer of primary syphilis here noticed 6 weeks ago. Initial infection is local and leads to development of a macule. This develops into a papule which then ulcerates to form a chancre (typically appears 9 to 90 days after exposure, usually between 2-3 weeks) and may not be noticed by the patient (as it is painless). It typically develops in the anogenital area or cervix. There may also be (discrete, painless, rubbery) regional lymphadenopathy. This ulcer heals spontaneously.

This patient has then gone on to develop secondary syphilis 6 weeks later (typically 4-8 weeks). Here there is disseminated treponemal infection which has multi-system manifestations and a diverse presentation. There are constitutional symptoms here as well as generalised lymphadenopathy. There may also, like this case, be this typical generalised symmetrical macular, papular or maculopapular diffuse rash which typically affects the palms of the hands and the plantar aspects of the feet. This rash may also occur on the trunk and scalp and may ulcerate. There may also be flesh-coloured wart-like lesions in the genital area which is known as condylomata lata.

The treatment is with penicillin. Untreated syphilis facilitates the transmission of HIV and can cause considerable problems such as cardiovascular and neurological disease, as well as a congenital syndrome in the newborn. In some parts of the developing world, syphilis in pregnancy is a major cause of miscarriage and stillbirth. Pregnant women with syphilis are at risk of transmitting the infection across the placenta to the fetus.

49
Q

A 32 year old man lacerated his leg in the garden. Two months later he developed a fever and headache followed by a permanent grin-like posture, inability to close his mouth, arching of his body with hyperextension of his neck.

What is the diagnosis?
A.	Herpes Zooster (Shingles)
B.	Toxoplasmosis
C.	CMV (cytomegalovirus)
D.	Tetanus
E.	Malaria
F.	Cholera
G.	Syphilis
H.	Rabies
I.	Polio
J.	Influenza
K.	Tuberculosis
L.	Viral Hepatitis
M.	Giardiasis
N.	HIV
O.	Glandular Fever
A

D. Tetanus

This is very obvious tetanus which is caused by the exotoxin of the bacterium Clostridium tetani. This should have been prevented by appropriate management of the initial tetanus-prone wound and with complete active immunisation, with passive immunisation given when required. There is trismus here which has resulted in a grimace which is described as ‘risus sardonicus’ or sardonic smile. During a generalised tetanic spasm, the patient classically arches their back and extends their legs, flexes their arms in abduction and clenches their fists. Apnoea may also be a feature of these spasms. Intermittent tonic contractions of skeletal muscles often occurs which causes intensely painful spasms which may last for minutes – these are often triggered by stimuli such as noise, light and physical contact. Tetanic spasms can also produce opisthotonus, board like abdominal wall rigidity, dysphagia and apnoeic periods. Management of clinical tetanus involves supportive care (airway management is crucial here as spasms may compromise ventilation – without mechanical ventilation facilities such as in the third world, asphyxia is the most common cause of death due to muscle spasm), wound debridement, antimicrobials, passive and active immunisation, control of spasms and the management of autonomic dysfunction. Case fatality rate is 12-53%.

50
Q

A 30 year old man recently returned from a holiday in Bangladesh. He developed watery diarrhoea 20 hours ago which has increased in volume. There has been vomiting. Now there is an almost continuous passage of loose and pale stools.

What is the diagnosis?
A.	Herpes Zooster (Shingles)
B.	Toxoplasmosis
C.	CMV (cytomegalovirus)
D.	Tetanus
E.	Malaria
F.	Cholera
G.	Syphilis
H.	Rabies
I.	Polio
J.	Influenza
K.	Tuberculosis
L.	Viral Hepatitis
M.	Giardiasis
N.	HIV
O.	Glandular Fever
A

F. Cholera

This is a secretory diarrhoea caused by the bacterial organism Vibrio cholerae. This organism releases a toxin which stimulates adenylate cyclase. It is classically a disease of poverty but is also well described in returning travellers. Vomiting is a common early feature. The most striking and characteristic feature of cholera is the loose rice-water stools – a high volume diarrhoea which remains pale and loose, without blood. The presentation tends to be with litres of this rice-water stools. Culture of the organism provides a definitive diagnosis and rapid dipstick tests are currently available. Most patients will recover if the effects of the profound volume depletion are corrected with either oral or IV rehydration. Antibiotics do shorten the duration and severity of disease but the rising rate of bacterial resistance is becoming a problem. Note that about 70-80% of those infected with Vibrio cholerae do remain asymptomatic.

What is interesting is that blood group O appears to lead to more severe disease, but may be protective against initial infection. Many infectious diseases indeed do show a relationship between blood group and disease susceptibility.

51
Q

A 20 year old man was bitten by a dog in France. 2 months later he developed a headache, fever and abnormal behaviour including the fear of water.

What is the diagnosis?
A.	Herpes Zooster (Shingles)
B.	Toxoplasmosis
C.	CMV (cytomegalovirus)
D.	Tetanus
E.	Malaria
F.	Cholera
G.	Syphilis
H.	Rabies
I.	Polio
J.	Influenza
K.	Tuberculosis
L.	Viral Hepatitis
M.	Giardiasis
N.	HIV
O.	Glandular Fever
A

This 20 year old man has rabies and is going to die. Symptomatic rabies is 100% fatal and there is no curative medical therapy. Palliative care is needed in this situation and given that spasms in rabies (hydrophobia and aerophobia) are very much stimulus driven, the recommendation is seclusion, room darkening and restraint. Rabies is one horrible way to die. Current recommendations are also to use haloperidol. Opioid analgesics may also be of use here as well as anticonvulsants for seizures and neuromuscular blockers. If interested, you can look up the Milwaukee protocol, the use of which has led to only 6 patients who have been known to survive symptomatic rabies without receiving the vaccine. This involves putting the patient into a drug induced coma and then giving them antiviral drugs. ‘Survival after Treatment of Rabies with Induction of Coma’ N Engl J Med 2005; 352:2508-2514 (Has some interesting videos too of ‘the girl who lived’)

Rabies is an acute viral encephalomyelitis caused by the rabies virus (Lyssavirus genus). It is transmitted by animal bites, especially dogs and bats. The incubation period varies and ranges from 5 days to 7 years. If post-exposure prophylaxis is given promptly with wound cleaning and immunisation and rabies Ig then this is very effective at preventing the disease. There is a non-specific prodrome. In encephalitic rabies, this is followed by eary behavioural changes and late paralysis. In the paralytic form, the behavioural changes are absent. Specific signs include hydrophobia, aerophobia and paraesthesias at the site of the bite wound. Death within 2 weeks is standard once symptomatic and the disease is rapidly progression.

52
Q

A 40 year old lady recently returned from a holiday in Leningrad developed tiredness, flatulence, abdominal bloating and loose stools.

What is the diagnosis?
A.	Herpes Zooster (Shingles)
B.	Toxoplasmosis
C.	CMV (cytomegalovirus)
D.	Tetanus
E.	Malaria
F.	Cholera
G.	Syphilis
H.	Rabies
I.	Polio
J.	Influenza
K.	Tuberculosis
L.	Viral Hepatitis
M.	Giardiasis
N.	HIV
O.	Glandular Fever
A

M. Giardiasis

Giardiasis (caused by Giardia lamblia) is an intestinal infection with a flagellated protozoan parasite which is transmitted faecal-orally (transmission is by ingestion of water or food contaminated with cysts, and by person to person spread). Symptoms vary from the asymptomatic passage of cysts to acute self limiting diarrhoea or chronic diarrhoea. Presenting symptoms aside from diarrhoea include abdominal bloating with cramps, frequent belching with a sulphuric smell, nausea, anorexia and fatigue. The diagnosis is made on the detection of cysts or trophozoites (the two morphological forms of Giardia which exist) in a stool sample. The first line treatment is with metronidazole or tinidazole.

53
Q

A 12 year old boy presents with a flu-like illness, fever, headache, vomiting, tremor of the left side of the body and weakness of his left leg.

What is the diagnosis?
A.	Herpes Zooster (Shingles)
B.	Toxoplasmosis
C.	CMV (cytomegalovirus)
D.	Tetanus
E.	Malaria
F.	Cholera
G.	Syphilis
H.	Rabies
I.	Polio
J.	Influenza
K.	Tuberculosis
L.	Viral Hepatitis
M.	Giardiasis
N.	HIV
O.	Glandular Fever
A

I. Polio

Poliovirus infection is usually asymptomatic and when symptomatic the most common presentation is with a minor GI illness. There is no cure for poliovirus infection and treatment is primarily supportive. This patient has acute flaccid paralysis (AFP), or paralytic poliomyelitis, which is the hallmark of major illness. This can rarely progress to bulbar paralysis and respiratory compromise. Paralytic poliomyelitis presents with decreased tone and motor function, as well as reduced tendon reflexes and muscle atrophy of the affected limb. Lack of vaccination is a strong risk factor. Remember that there are two main types of polio vaccine – Sabin, which is the oral weakened strain in disease endemic regions, and Salk, which is inactivated poliovirus in the rest of the world.

54
Q

A 22 year old woman presents with a postcoital bleed but denies having other symptoms. She is currently in a relationship but is concerned that her partner is having sex with other women. Examination with a speculum reveals a mucopurulent yellow and cloudy discharge from the cervical os. The cervix is friable.

What is the diagnosis?

  1. Trichomonas vaginitis
  2. Vaginal candidiasis
  3. Bacterial vaginosis
  4. Chlamydia
A
  1. Chlamydia

This is genital tract chlamydia infection which is one of the most common STDs in the world. Remember that many infected individuals are asymptomatic. Women may present with cervical inflammation or yellow, cloudy discharge from the cervical os. A friable cervix is often also found on examination – the cervix bleeds easily with friction from a Dacron swab.

55
Q

A 5 year old boy presents with a fever, headache and a very itchy vesicular rash mainly on his chest and face. He has recently taking paracetamol for a sore throat. There has also been a high fever in the last 24 hours. Lung fields are however clear on CXR. In some areas the lesions are crusted over while in others they appear to be newly formed. A classmate at school has had similar symptoms recently.

What is the diagnosis?

  1. Stevens-Johnson syndrome
  2. Scabies
  3. Bartonella
  4. Varicella zoster
A
  1. Varicella zoster

This is VZV infection (chickenpox) which typically presents with a fever, malaise and a widespread vesicular and pruritic rash which primarily affects the torso and face. Most countries in Europe do not immunise children against varicella.

56
Q

A 58 year old man with uncontrolled HIV infection and AIDS presents with 2 week history of blurred vision bilaterally. He also reports seeing visual floaters. Examination reveals a man who is severely cachectic with generalised lymphadenopathy. Fundoscopy reveals creamy coloured areas with overlying retinal haemorrhages.

What is the diagnosis?

  1. Mycobacterium avium complex
  2. Human herpes virus 6
  3. Infectious mononucleosis
  4. Cytomegalovirus
A
  1. Cytomegalovirus

This is a presentation of CMV retinitis, which is the most common manifestation of CMV disease in AIDS, the second most common being colitis. However do remember that virtually any organ can be affected by CMV and it can cause a range of conditions from encephalitis to pneumonitis. In CMV retinitis, fundoscopy will reveal areas of infarction, haemorrhage, perivascular sheathing and retinal opacification. These findings here are of chorioretinitis.

57
Q

A 18 year old student from Malaysia presents with 3 days of continuously high fevers. There are also general aches and pains and a predominantly frontal headache with retro-orbital pain which gets worse on eye movement. Examination reveals hypotension, tachycardia and a generalised skin flush with warm peripheries. There is also mild thrombocytopenia, elevated LFTs and low WBC count.

What is the diagnosis?

  1. Dengue fever
  2. Leptospirosis
  3. Rickettsia
  4. Rubella
A
  1. Dengue fever

Dengue in endemic in over 100 countries, especially SE Asia, Western Pacific and the Americas. It is an arbovirus which is transmitted by the Aedes aegypti mosquito found in the tropical and subtropical parts of the world. Clinical features include fever, headache, myalgia/arthralgia, skin flush and leucopenia, thrombocytopenia and elevated LFTs. Viral antigen or nucleic acid detection and serology are confirmatory tests to perform.

58
Q

A 35 year old homosexual man with HIV presents to his GP after a holiday in Barcelona having recently noticed the presence of painless purple skin plaques on his lower legs and some generalised rubbery lumps located over his body. Examnation reveals that there is also a purple coloured mass on his hard palate.

What is the diagnosis?

  1. Seborrhoeic dermatitis
  2. Human papillomavirus
  3. Photodermatitis
  4. Kaposi sarcoma
A
  1. Kaposi sarcoma

This is Kaposi sarcoma which is a low-grade neoplasm caused by human herpesvirus-8 (or KSHV). It is associated with the acquired immunodeficiency associated with HIV infection. Oral KS can frequently affect the hard palate, gums and dorsum of the tongue. Cutaneous lesions are purple in colour and usually painless and non-pruritic. Histopathology of these vascular lesions will show characteristic atypical spindle-shape cells.

59
Q

A 64 year old smoker is referred to the doctors by his dentist, who noticed a white coloured plaque on the lateral tongue margin and the floor of the mouth. It has a thickened, white and leathery appearance on examination. The surrounding mucosa is clinically normal. He has recently has a kidney transplant. In situ hybridisation confirms the diagnosis.

What is the diagnosis?

  1. Candidiasis
  2. Oral hairy leukoplakia
  3. Squamous cell carcinoma
  4. Syphilitic leukoplakia
A
  1. Oral hairy leukoplakia

This is oral hairy leukoplakia which presents as a painless white plaque found along the lateral tongue borders. There is history here which suggests immunosuppression. In situ hybridisation here has demonstrated the presence of EBV in the tissue.

60
Q

A sexually active female student presents having noticed pearly umbilicated papules on her thigh which feel smooth to the touch. She tells you that these are itchy. Examination reveals local erythema around these lesions.

What is the diagnosis?

  1. Molluscum contagiosum
  2. Genital warts
  3. Lymphogranuloma venereum
  4. Pelvic inflammatory disease
A
  1. Molluscum conatgiosum

This is molluscum contagiosum which is sexually transmitted in adulthood. Lesions appear as the umbilicated pearly and smooth papules mentioned. About a third of patients will also develop symptoms of local redness, swelling or pruritis. Adults should be treated for this STD.

61
Q

A 22 year old man notices a painless penile ulcer. He has recently started his first sexually active relationship. His partner has no symptoms and he is also otherwise well. Examination reveals an indurated ulcer with rubbery and moderate inguinal lymphadenopathy.

What is the diagnosis

  1. Chancroid
  2. Primary HIV infection
  3. Syphilis
  4. Genital herpes
A
  1. Syphilis

The chance of primary syphilis is usually a solitary, painless and clean ulcer with an indurated base. This is a common sexually transmitted infection caused by the spirochete Treponema pallidum. Treatment is with penicillin – untreated infection can cause considerable morbidity and facilitates HIV transmission.

62
Q

A 35 year old woman who loves birds presents with a 10 day history of a low grade fever and a recent 2 day history of a cough which is non-productive. Examination reveals diffuse crackles on chest examination and mild hepatomegaly which is tender on palpation.

What is the diagnosis

  1. Mycoplasma
  2. Psittacosis
  3. Legionella
  4. Q fever
A
  1. Psittacosis

Chlamydia psittaci causes a community-acquired atypical pneumonia. It is often acquired from domesticated or commercially raised birds or exotic imported birds. The presentation can be similar to Mycoplasma and Chlamydophila pneumoniae. Tetracyclines are the preferred treatment. Hepatomegaly can occur in this condition with pain on palpation but is uncommon, as can splenomegaly. Both organs, if enlarged, are diffusely so.

63
Q

A 3 year old girl presents with a week history of pain in the abdomen and watery diarrhoea which became bloody after the first 8 hours. Three days before, she had distinctly recalled consuming a burger which may have been undercooked. Investigations show a mild anaemia and thrombocytopenia with blood smear demonstrating multiple schistocytes. Creatinine is also raised.

What is the diagnosis

  1. Haemolytic-uraemic syndrome
  2. Antiphospholipid syndrome
  3. Disseminated intravascular coagulation
  4. HELLP syndrome
A
  1. Haemolytic-uraemic syndrome

This is haemolytic uraemic syndrome which is characterised by MAHA, thrombocytopenia and nephropathy. Most cases are in children and related to gastroenteritis caused by verotoxin producing E. coli (O157:H7). The presence of schistocytes establishes the presence of thrombotic microangiopathy. The anaemia, thrombocytopenia and renal dysfunction characterised by creatinine rise mark this diagnosis.

64
Q

A 12 year old boy came back from summer camp and was taken to A&E feeling hot with vomiting and a sore throat. Laboratory tests and CXR is unremarkable and he is discharged. He returns later the same day with paraesthesias of the right arm and scalp, dysphagia and ataxia. When presented with water, he goes into laryngeal spasm and feels he is choking. Placement of nasal cannulae to give oxygen has the same effect.

What is the diagnosis?

  1. Attention seeking behaviour
  2. Rabies
  3. Guillain-Barre syndrome
  4. West Nile virus encephalitis
A
  1. Rabies

This is rabies, which can be difficult to diagnose if there is the absence of identifiable rabies exposure. There is non-specific prodrome of fever, chills, malaise, sore throat, vomiting, headaches and paraesthesias. The most specific signs of the disease are displayed here with hydrophobia and aerophobia (elicited by the placement of nasal cannulae). This patient is going to die and palliative care is needed. Rabies is considered 100% fatal.

65
Q

A 13 year old presents with fever and sore joints. She has had a sore throat about 3 weeks ago but did not see a doctor about it. While waiting in A&E she develops choreiform movements of the whole body and head with facial expressions that resemble grimaces.

What is the diagnosis?

  1. Septic arthritis
  2. Borrelia burgdorferi
  3. Clostridium tetani
  4. Streptococcus pyogenes
A
  1. Streptococcus pyogenes

This girl has rheumatic fever which is caused by an autoimmune process following infection with group A streptococci. The 5 major manifestations of acute rheumatic fever is something you need to be aware of. They are carditis, polyarthritis, chorea, erythema marginatum and SC nodules. Various other signs can also be seen such as spooning sign and pronator sign.

66
Q

A man from Tanzania presents with occassional diarrhoea accompanied by frank blood. Examination reveals mild hepatomegaly and a palpable spleen. On further questioning, he tells you he has been swimming in the local lake.

What is the diagnosis?

  1. Salmonella
  2. Leishmaniasis
  3. Schistosomiasis
  4. Toxoplasmosis
A
  1. Schistosomiasis

This is caused by a fluke which is acquired through exposure of the skin to contaminated freshwater (it is a snail-borne parasite). Patients can present acutely with bloody diarrhoea and hepatosplenomegaly is a common finding too. Diagnosis is made on microscopic visualisation of eggs in stools or urine. The preferred treatment for schistosome infections is with a drug called praziquantel.

67
Q

A 73 year old cut his hand while gardening. He presents with lock jaw which results in a grimace. There are also intermittent tonic contractions of his muscles which are painful and last for minutes.These are sometimes triggered by noise.

What is the diagnosis

  1. Tetanus
  2. Generalised seizure
  3. Diphtheria
  4. Hypocalcaemia
A
  1. Tetanus

This is caused by the exotoxin of Clostridium tetani and there is trismus here (lock jaw) which has resulted in risus sardonicus. The intermittent tonic contractions are also characteristic and the spasms can be triggered by both external and internal stimuli.