Blackboard Infectious Diseases EMQs Flashcards
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
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.
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
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.
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
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).
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
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.
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
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.
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
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.
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
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.
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
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.
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
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.
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
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.
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
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.
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
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.
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
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.
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
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.
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
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.
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
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.
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
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.
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. 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.
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
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.
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
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.
A note from the lecturer on which pathogens to learn
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…)
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
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.
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. 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.
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
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.
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
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.
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
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.
