infectious disease Flashcards
what is rheumatic fever
AI condition triggered by strep A bacteria
Usually strep pyogenes (tonsilitis)
Multi-system affecting joints, heart, skin + nervous system
Type 2 hypersensitivity reaction (2-3 wks after inital infection)
rheumatic fever presentation
2 – 4 weeks following a streptococcal infection, such as tonsillitis.
Fever
Joint pain - diff ones at diff times
Rash - Erythema marginatum (pink rings)
Shortness of breath
Chorea
Subcutaneous nodules
jones criteria for rheumatic fever+ what you need for dx
Dx when there is evidence of recent streptococcal infection, plus:
Two major criteria OR
One major criteria plus two minor criteria
Major Criteria:
J – Joint arthritis
O – Organ inflammation, such as carditis
N – Nodules
E – Erythema marginatum rash
S – Sydenham chorea
Minor Criteria:
F - Fever
E - ECG Changes (prolonged PR interval) without carditis
A - Arthralgia without arthritis
R - Raised inflammatory markers (CRP and ESR)
rheumatic fever ix
Throat swab for bacterial culture
ASO antibody titres (show prev group A strep infection)
Echocardiogram, ECG and chest xray can assess the heart involvement
A diagnosis of rheumatic fever is made using the Jones criteria
rheumatic fever tx
Tonsillitis caused by streptococcus should be treated with phenoxymethylpenicillin (penicillin V) for 10 days.
Patients with clinical features of rheumatic fever should be referred immediately for specialist management.
NSAIDs for joint pain
Aspirin and steroids for treat carditis
Prophylactic antibiotics (oral or intramuscular penicillin) are used to prevent further streptococcal infections and recurrence of the rheumatic fever. These are continued into adulthood.
Monitoring and management of complications
what type of pneumonia do you get in immunocompromised px
Pneumocystis pneumonia (PCP) caused by the pneumocystis jiroveci fungus
get in HIV no meds or after transplant
fever
non-productive cough
breathlessness on exertion
diagnostic ix for PCP
bronchoscopy w bronchoalveolar lavage
(in practise often sputum samples for PCR, less invasive)
test to check for h pylori eradication
urea breath test
what gut prob can c diff cause
pseudomembranous colitis
what abx cause c diff
cephalosporins
e.g. cefuroxime and cefoxitin; ceftriaxone and ceftazidime
other RF = PPIs
c diff histology
g +ve , spore-forming, exotoxin producing bacillus
mx of c diff first infection
oral vancomycin 10 days
second-line therapy: oral fidaxomicin
third-line therapy: oral vancomycin +/- IV metronidazole
recurrent ep c diff mx
within 12 wks of prev = oral fidaxomicin
> 12 wks = oral vancomycin OR fidaxomicin
life threatening c diff mx
oral vancomycin AND IV metronidazole
what is the most common organism causing septic arthritis in young adults who are sexually active
Neisseria gonorrhoeae
what is the overall most common organism causing septic arthritis
s aureus
histology of Neisseria gonorrhoeae
Gram negative diplococci
histology of s aureus
Gram positive staphylococci
mx of wounds re tetanus
if have had full course of 5 vaccines
if not had any
if unsure
Patient has had a full course of tetanus vaccines, with the last dose < 10 years ago
- no vaccine nor tetanus immunoglobulin is required, regardless of the wound severity
Patient has had a full course of tetanus vaccines, with the last dose > 10 years ago
- if tetanus prone wound: reinforcing dose of vaccine
- high-risk wounds (e.g. compound fractures, delayed surgical intervention, significant degree of devitalised tissue): reinforcing dose of vaccine + tetanus immunoglobulin
If vaccination history is incomplete or unknown
- reinforcing dose of vaccine, regardless of the wound severity
- for tetanus prone and high-risk wounds: reinforcing dose of vaccine + tetanus immunoglobulin
what to do if in community + suspect bacterial meningitis
transfer to hx urgently
IM benzylpenicillin
what warning signs in suspected bacterial meningitis would prompt a senior review
rapidly progressive rash
poor peripheral perfusion
respiratory rate < 8 or > 30 / min or pulse rate < 40 or > 140 / min
pH < 7.3 or WBC< 4 *109/L or lactate > 4 mmol/L
GCS < 12 or a drop of 2 points
poor response to fluid resuscitation
when to delay lumbar puncture in suspected bacterial meningitis
signs of severe sepsis or a rapidly evolving rash
severe respiratory/cardiac compromise
significant bleeding risk
signs of raised intracranial pressure
- focal neurological signs
- papilloedema
- continuous or uncontrolled seizures
- GCS ≤ 12
mx of px w suspected bacterial meningitis where LP isn’t CI
IV access → take bloods and blood cultures
lumbar puncture
- if cannot be done within the first hour, IV antibiotics should be given after blood cultures have been taken
IV antibiotics
< 3 months = cefotaxime + amoxicillin (or ampicillin)
3 months-50 years = cefotaxime (or ceftriaxone)
> 50 years = cefotaxime (or ceftriaxone) + amoxicillin (or ampicillin)
consider IV dexamethasone
- avoid in septic shock, meningococcal septicaemia, or if immunocompromised, or in meningitis following surgery’
CT scan is not normally indicated
mx of meningitis px w signs of raised ICP
get critical care input
secure airway + high-flow oxygen
IV access → take bloods and blood cultures
IV dexamethasone
IV antibiotics as above
arrange neuroimaging
meningitis prophylaxis for close contacts (within 7 days b4 onset)
oral ciprofloxacin single dose
CSF in LP of bacterial meningitis
cloudy
high level of protein
low level of glucose
high WCC - mainly neutrophils
think that the bacteria swimming in the CSF will release proteins and use up the glucose.
CSF in LP of viral meningitis
clear
slightly raised/normal level of protein
normal level of glucose
high WCC - mainly lymphocytes
what is lyme disease caused by
the spirochaete Borrelia burgdorferi and is spread by ticks
early features of lyme disease
Early features (within 30 days)
erythema migrans
- ‘bulls-eye’ rash is typically at the site of the tick bite
- typically develops 1-4 weeks after the initial bite but may present sooner
- usually painless, more than 5 cm in diameter and slowly increases in size
- present in around 80% of patients.
systemic features
- headache
- lethargy
- fever
- arthralgia
mx of cellulitis (class 1)
oral flucloxacillin as first-line treatment for mild/moderate cellulitis
oral clarithromycin, erythromycin (in pregnancy) or doxycycline is recommended in patients allergic to penicillin
Management of suspected/confirmed Lyme disease
doxycycline if early disease. Amoxicillin is an alternative if doxycycline is contraindicated (e.g. pregnancy)
- people with erythema migrans should be commenced on antibiotic without the need for further tests
ceftriaxone if disseminated disease
what to do before tuberculosis vaccine
tuberculin skin test
The only exceptions are children < 6 years old who have had no contact with tuberculosis
what is infectious mononucleosis (glandular fever) caused by
EBV
infectious mononucleosis (glandular fever) presentation
sore throat
lymphadenopathy
pyrexia
test for infectious mononucleosis (glandular fever)
monospot test
tx infectious mononucleosis (glandular fever)
supportive
avoid contact sports for 4 weeks
what to do if you have been exposed to hep B
if had HBV vaccine - see if you are a vaccine responder/non-responder
non-responder = anti-HBs < 10mIU/ml 1-2 months post-immunisation)
if responder
- give booster dose
if non-responder
- hepatitis B immune globulin (HBIG) and a booster vaccine
what is TB caused by
Mycobacterium tuberculosis, a small rod-shaped bacteria (a bacillus)
how to stain mycobacterium tuberculosis
Zeihl-Neelsen stain for acid-fast bacilli that will stain red
TB disease course
Immediate clearance of the bacteria (in most cases)
Primary active tuberculosis (active infection after exposure)
Latent tuberculosis (presence of the bacteria without being symptomatic or contagious)
Secondary tuberculosis (reactivation of latent tuberculosis to active infection)
what is military TB
When the immune system cannot control the infection + disseminated and severe disease develops
what is a cold abscess
A firm, painless abscess caused by tuberculosis, usually in the neck. They do not have the inflammation, redness and pain you expect from an acutely infected abscess.
RFs TB
Close contact with active tuberculosis (e.g., a household member)
Immigrants from areas with high tuberculosis prevalence
People with relatives or close contacts from countries with a high rate of TB
Immunocompromised (e.g., HIV or immunosuppressant medications)
Malnutrition, homelessness, drug users, smokers and alcoholics
what type of vaccine is BCG
live attenuated
what to do before BCG vaccine
tested with the Mantoux test and only given the vaccine if this test is negative
assessed for the possibility of immunosuppression and HIV due to the risks related to a live vaccine.
TB presentation
chronic, gradually worsening symptoms. Most cases involve pulmonary disease
Cough
Haemoptysis
Lethargy
Fever or night sweats
Weight loss
Lymphadenopathy
Erythema nodosum
Spinal pain in spinal tuberculosis (Pott’s disease of the spine)
tests for an immune response to TB caused by previous infection, latent TB or active TB
Mantoux test
Interferon‑gamma release assay (IGRA)
ix to do when active TB is suspected
Chest x-ray
= upper lobe cavitation is the classical finding of reactivated TB
= bilateral hilar lymphadenopathy
Sputum cultures GS - allows for the identification of antibiotic sensitivities and resistance, guiding treatment
(can do sputum smear but not as sensitive)
- 3 specimens are needed
- stained for the presence of acid-fast bacilli (Ziehl-Neelsen stain)
NAAT
Disseminated miliary TB CXR
millet seeds uniformly distributed across the lung fields
tx active TB
R – Rifampicin for 6 months
I – Isoniazid for 6 months
P – Pyrazinamide for 2 months
E – Ethambutol for 2 months
SE of isoniazid + how to help
peripheral neuropathy
“I’m-so-numb-azid”
pyridoxine (vitamin B6) is co-prescribed to help prevent this - remember as you take it for 6 months
SE rifampicin
red/orange discolouration of secretions, such as urine and tears
“red-I’m-pissin”
potent cytochrome P450 inducer -> reduces the effects of drugs metabolised by this system, such as COCP
SE pyrazinamide
hyperuricaemia (high uric acid levels) -> gout and kidney stones.
hepatotoxicity
arthralgia
sideroblastic anaemia
SE ethambutol
colour blindness and reduced visual acuity
“eye-thambutol”
optic neuritis
which TB drugs are hepatotoxic
Rifampicin, isoniazid and pyrazinamide
presentation genital herpes
painful genital ulceration
- may be associated with dysuria and pruritus
the primary infection is often more severe than recurrent episodes
- systemic features such as headache, fever and malaise are more common in primary episodes
tender inguinal lymphadenopathy
urinary retention may occur
ix genital herpes
nucleic acid amplification tests (NAAT)
mx genital herpes
oral aciclovir
rabies features
prodrome: headache, fever, agitation
hydrophobia: water-provoking muscle spasms
hypersalivation
Negri bodies: cytoplasmic inclusion bodies found in infected neurons
following animal bite in countries where there is a risk of rabies
the wound should be washed
if an individual is already immunised then 2 further doses of vaccine should be given
if not previously immunised then human rabies immunoglobulin (HRIG) should be given along with a full course of vaccination. If possible, the dose should be administered locally around the wound
what is dengue fever
viral disease of the tropics, transmitted by mosquitoes, and causing sudden fever and acute pains in the joints.
can progress to viral haemorrhagic fever
dengue fever classification
dengue fever:
- without warning signs
- with warning signs
severe dengue (dengue haemorrhagic fever)
dengue fever presentation
FEVER
HEADACHE (often retro-orbital)
myalgia, bone pain and arthralgia (‘break-bone fever’)
pleuritic pain
facial flushing (dengue)
maculopapular RASH
haemorrhagic manifestations
e.g. positive tourniquet test, petechiae, purpura/ecchymosis, epistaxis
dengue fever warning signs
abdominal pain
hepatomegaly
persistent vomiting
clinical fluid accumulation (ascites, pleural effusion)
Severe dengue (dengue haemorrhagic fever)
a form of disseminated intravascular coagulation (DIC) resulting in:
- thrombocytopenia
- spontaneous bleeding
around 20-30% of these patients go on to develop dengue shock syndrome (DSS)
ix dengue fever
typical blood results:
- leukopenia
- thrombocytopenia
- raised aminotransferases
diagnostic tests:
- serology
- NAAT for viral RNA
- NS1 antigen test
tx dengue fever
entirely symptomatic e.g. fluid resuscitation, blood transfusion etc
no antivirals are currently available
what is dengue fever caused by
Aedes aegypti mosquito
endemic in INDIA
7 days incubation
what is chlamydia caused by
Chlamydia trachomatis
ix chlamydia
NAAT
- for women: the vulvovaginal swab is first-line
- for men: the urine test is first-line (first void)
2 wks after poss exposure
chlamydia tx
1st line
if pregnant
1st line = doxycyline 7 days
if pregnant = azithromycin, erythromycin or amoxicillin
most common cause of viral meningitis
enteroviruses - coxsackie virus, echovirus
mx BV
asx = no tx
sx = oral metronidazole 5-7 days
criteria for BV dx
thin, white homogenous discharge
CLUE cells on microscopy: stippled vaginal epithelial cells
vaginal pH > 4.5
positive WHIFF test (addition of potassium hydroxide results in fishy odour)
leprosy causative organism
Mycobacterium leprae
sx leprosy + what country can get it
endemic to certain areas of india
hypo-pigmented patches
loss of sensation in fingers + toes
thickening of peripheral nerves (ulnar)
thickening of skin on hands + face - leonine faces
muscle weakness
leprosy tx
dapsone, rifampicin and clofazimine for 12–24 months
test for all mycobacterium
Acid-fast bacillus (AFB) smears
commonest bacterial cause of intestinal disease in UK
Campylobacter jejuni
features campylobacter jejuni
faecal-oral route
incubation period = 1-6 days
prodrome: headache malaise
diarrhoea: often bloody
abdominal pain: may mimic appendicitis
tx campylobacter jejuni
tx if severe / px immunocomp
clarithromycin
(or ciprofloxacin)
comps of campylobacter jejuni
Guillain-Barre syndrome may follow Campylobacter jejuni infections
reactive arthritis
septicaemia, endocarditis, arthritis
causes of meningitis 0-3months old
Group B Streptococcus (most common cause in neonates)
E. coli
Listeria monocytogenes
causes of meningitis 3-6 yrs old
Neisseria meningitidis
Streptococcus pneumoniae
Haemophilus influenzae
causes of meningitis 6-60 yrs old
Neisseria meningitidis
Streptococcus pneumoniae
causes of meningitis >60 yrs old
Streptococcus pneumoniae
Neisseria meningitidis
Listeria monocytogenes
causes of meningitis if immunosuppressed
Listeria monocytogenes
e coli gram stain
gram negative bacilli
Streptococcus pneumoniae gram stain
gram positive diplococci/chain
H. influenzae gram stain
gram negative coccobacilli
Listeria monocytogenes gram stain
gram positive rod
Neisseria meningitis gram stain
gram negative diplococci
Staphylococcal toxic shock syndrome dx criteria
fever: temperature > 38.9ºC
hypotension: systolic blood pressure < 90 mmHg
diffuse erythematous rash
desquamation of rash, especially of the palms and soles
involvement of three or more organ systems: e.g. gastrointestinal (diarrhoea and vomiting), mucous membrane erythema, renal failure, hepatitis, thrombocytopenia, CNS involvement (e.g. confusion)
what test sld be offered to all px w TB
HIV
difference between IgM and IgG
IgM raised 4-7 days after infection starts
iMmediately
IgG raised 7-14 days post-infection and are detected for weeks, months, even years later (if positive shows immunity)
Gradually
examples of Encapsulated Bacteria
Streptococcus pneumoniae
Haemophilus influenzae
Meningococci
- the spleen plays a central role in opsonizing and phagocytosing encapsulated bacteria
what are howell-jolly bodys
pathognomonic for splenic dysfunction
organism that causes syphilis
treponema pallidum
serological tests for syphilis
non-treponemal tests
- non specific, can have false +ves
- assesses quantity of antibodies being produced
- becomes -ve after tx
- decreases over time
-VDRL or RPR
treponemal-specific tests
- more complex + expensive but specific
- ‘reactive’ or ‘non-reactive’
- always has TP in its name (eg TPHA or TPEIA)
Causes of false positive non-treponemal (cardiolipin) tests
pregnancy
SLE, anti-phospholipid syndrome
tuberculosis
leprosy
malaria
HIV
Positive non-treponemal test + positive treponemal test
consistent with active syphilis infection
Positive non-treponemal test + negative treponemal test
consistent with a false-positive syphilis result e.g. due to pregnancy or SLE (see list above)
Negative non-treponemal test + positive treponemal test :
consistent with successfully treated syphilis
primary features of syphilis
chancre - painless ulcer at site of sexual contact
local non-tender lymphadenopathy
(often not seen in women)
secondary features of syphilis
6-10 wks after primary infection
systemic sx: fevers, lymphadenopathy (not painful)
RASH on trunk, palms, soles
buccal ‘snail track’ ulcers
condylomata lata (painless, warty lesions on the genitalia)
tertiary features of syphilis
gummas (granulomatous lesions of the skin + bones)
ascending aortic aneurysms
general paralysis of the insane
tabes dorsalis
Argyll-Robertson pupil (no reaction to light but do accomodation)
features of congenital syphilis
blunted upper incisor teeth (Hutchinson’s teeth), ‘mulberry’ molars
rhagades (linear scars at the angle of the mouth)
keratitis
saber shins
saddle nose
deafness
ebola incubation period
2 to 21 days
sx ebola
sudden onset of fever fatigue, muscle pain, headache and sore throat.
This is followed by vomiting, diarrhoea, rash, symptoms of impaired kidney and liver function, and in some cases, both internal and external bleeding
how is ebola spread
human-to-human transmission via direct contact (through broken skin or mucous membranes) with the blood, secretions, organs or other bodily fluids of infected people, and with surfaces and materials (e.g. bedding, clothing) contaminated with these fluids
Most common organism found in central line infections
Staphylococcus epidermidis (as part of normal skin flora)
1st line syphilis treatment
intramuscular BENZATHINE PENICILLIN
causes of non-falciparum malaria
Plasmodium vivax most common
Plasmodium ovale
Plasmodium malariae
Plasmodium knowlesi
features of non-falciparum malaria
general features of malaria: fever, headache, splenomegaly
Plasmodium vivax/ovale: cyclical fever every 48 hours. Plasmodium malariae: cyclical fever every 72 hours
Plasmodium malariae: is associated with nephrotic syndrome
Ovale and vivax malaria have a hypnozoite stage and may therefore relapse following treatment.
tx of non-falciparum malaria
in areas which are known to be chloroquine-sensitive: either CHLOROQUINE or an artemisinin-based combination therapy (ACT)
in areas which are known to be chloroquine-resistant: an ACT (avoid in pregnant women)
patients with ovale or vivax malaria should be given PRIMAQUINE following acute treatment with chloroquine to destroy liver hypnozoites and prevent relapse
how to differentiate between toxoplasmosis + primary CNS lymphoma in HIV px
toxoplasmosis:
- multiple lesions
- ring or nodular enhancement
- Thallium SPECT negative
lymphoma:
- single lesion
- solid (homogenous) enhancement
- Thallium SPECT positive
presentation PCP
presents desaturation on exertion
often Chest x-ray appears normal
dyspnoea
dry cough
fever
very few chest signs
Pneumothorax is a common complication
mx PCP
co-trimoxazole
Pseudomonas aeruginosa lab features (+ gram stain)
Gram-negative rod
non-lactose fermenting
oxidase positive
2 common bacteria that cause otitis externa
Pseudomonas aeruginosa
Staphylococcus aureus
Gram -ve rods: CHEPS (rods like chips)
C. Jejuni
H. influenzae
E. Coli
Pseudomonas
Salmonella
Klebsiella pneumoniae
features of trichomonas vaginalis
vaginal discharge: offensive, yellow/green, frothy
vulvovaginitis
strawberry cervix
pH > 4.5
in men is usually asymptomatic but may cause urethritis
ix trichomonas vaginalis
microscopy of a wet mount shows motile trophozoites
tx trichomonas vaginalis
oral metronidazole for 5-7 days, although the BNF also supports the use of a one-off dose of 2g metronidazole
HIV post exposure prophylaxis
oral antiretroviral therapy for 4 weeks (should be initiated immediately after exposure but can be considered for up to 72 hours)
complications of Mycoplasma pneumoniae
erythema multiforme (target lesions), nodosum
cold agglutins (IgM): may cause an AI haemolytic anaemia, thrombocytopenia
meningoencephalitis, GBS and other immune-mediated neurological diseases
bullous myringitis (painful vesicles on the tympanic membrane)
pericarditis/myocarditis
gastrointestinal: hepatitis, pancreatitis
renal: acute glomerulonephritis
features of Mycoplasma pneumoniae
the disease typically has a prolonged and gradual onset
flu-like symptoms classically precede a dry cough
bilateral consolidation on x-ray
complications may occur
ix Mycoplasma pneumoniae
diagnosis is generally by Mycoplasma SEROLOGY
positive cold agglutination test → peripheral blood smear may show red blood cell agglutination
when to send a urine culture in LUT infection sx
aged > 65 years
visible or non-visible haematuria
men
pregnant
bacteria in BV
Gardnerella vaginalis
what is cellulitis
a bacterial infection that affects the dermis and the deeper subcutaneous tissues
causes of celluliis
Streptococcus pyogenes
less commonly Staphylcoccus aureus
features of cellulitis
commonly occurs on the shins
- usually unilateral - bilateral cellulitis is rare and suggests an alterative diagnosis
erythema
- generally reasonably well-defined margins but some cases may present with diffuse erythema
- blisters and bullae may be seen with more severe disease
swelling
systemic upset
- fever
- malaise
- nausea
CLINICAL DX
classification for cellulitis
Eron classification
I = no signs of systemic toxicity, no uncontrolled co-morbidities
II = either systemically unwell or systemically well but with a co-morbidity (e.g. PAD chronic venous insufficiency, or morbid obesity) which may complicate or delay resolution of infection
III = significant systemic upset such as acute confusion, tachycardia, tachypnoea, hypotension, or unstable co-morbidities that may interfere with a response to treatment, or a limb-threatening infection due to vascular compromize
IV = sepsis syndrome or a severe life-threatening infection such as necrotizing fasciitis
who with cellulitis to admit for IV abx
Has Eron Class III or Class IV cellulitis.
Has severe or rapidly deteriorating cellulitis (for example extensive areas of skin).
Is very young (under 1 year of age) or frail.
Is immunocompromized.
Has significant lymphoedema.
Has facial cellulitis (unless very mild) or periorbital cellulitis.
mx cellulitis according to classification
Eron Class I
- oral FLUCLOXACILLIN as first-line treatment for mild/moderate cellulitis
- oral clarithromycin, ERYTHROMYCIN (in pregnancy) or doxycycline is recommended in patients allergic to penicillin
Eron Class II
- NICE recommend: ‘Admission may not be necessary if the facilities and expertise are available in the community to give intravenous antibiotics and monitor the person - check local guidelines.’
Eron Class III-IV
- admit
- NICE recommend: oral/IV co-amoxiclav, oral/IV clindamycin, IV cefuroxime or IV ceftriaxone
features of gonorrhoea
males: urethral discharge, dysuria
females: cervicitis e.g. leading to vaginal discharge
rectal and pharyngeal infection is usually asymptomatic
mx gonorrhoea
single dose of IM ceftriaxone 1g
If sensitivities are known (and the organism is sensitive to ciprofloxacin) then a single dose of oral ciprofloxacin 500mg should be given
what is the Jarisch-Herxheimer reaction
sometimes seen following tx of syphilis
-> fever, rash, tachycardia after 1st dose of abx
(no wheeze/hypotension differentiating it from anaphylaxis)
no treatment is needed other than antipyretics
what to monitor to asses response to syphilis tx
nontreponemal (rapid plasma reagin [RPR] or Venereal Disease Research Laboratory [VDRL]) titres should be monitored after treatment to assess the response
a fourfold decline in titres (e.g. 1:16 → 1:4 or 1:32 → 1:8)is often considered an adequate response to treatment
ix lyme disease
can be diagnosed clinically if erythema migrans is present
enzyme-linked immunosorbent assay (ELISA) antibodies to Borrelia burgdorferi are the first-line test
Botulism features
patient usually fully conscious with no sensory disturbance
flaccid paralysis
diplopia
ataxia
bulbar palsy
Clostridium botulinum
gram positive anaerobic bacillus
7 serotypes A-G
produces botulinum toxin, a neurotoxin which irreversibly blocks the release of acetylcholine
may result from eating contaminated food (e.g. tinned) or intravenous drug use
neurotoxin often affects bulbar muscles and autonomic nervous system
tx botulism
botulism antitoxin (only effective if given early) and supportive care
extra features of infectious mononucleosis (glandular fever)
palatal petechiae
splenomegaly - predisposes to rupture
hepatitis - transient rise in ALT
lymphocytosis
haemolytic anaemia secondary to cold agglutins (IgM)
what happens to some px who take penicillins w infectious mononucleosis (glandular fever)
a maculopapular, pruritic rash develops in around 99% of patients
what organism causes TSS
staph aureus
sx mumps
fever
malaise, muscular pain
parotitis (earache, pain on eating) - unilateral initially then becomes bilateral in 70%
comps of mumps
orchitis - uncommon in pre-pubertal males but occurs in around 25-35% of post-pubertal males. Typically occurs four or five days after the start of parotitis
hearing loss - usually unilateral and transient
meningoencephalitis
pancreatitis
malignancies assoc w EBV infection
Burkitt’s lymphoma*
Hodgkin’s lymphoma
nasopharyngeal carcinoma
HIV-associated central nervous system lymphomas
Characteristic features of pneumococcal pneumonia (strep pneumoniae)
rapid onset
high fever
pleuritic chest pain
herpes labialis (cold sores)
cause of bronchiolitis
RSV
cause of croup
parainfluenza
cause of common cold
rhinovirus
cause of flu
influenza virus
most common cause of CAP
Streptococcus pneumoniae
Most common cause of bronchiectasis exacerbations
Haemophilus influenzae
cause of epiglottitis
Haemophilus influenzae
what is the most common, most severe type of malaria
Falciparum malaria
clinical features + comps of severe malaria
schizonts on a blood film
parasitaemia > 2%
hypoglycaemia
acidosis
temperature > 39 °C
severe anaemia
Complications
cerebral malaria: seizures, coma
acute renal failure: blackwater fever, secondary to intravascular haemolysis, mechanism unknown
acute respiratory distress syndrome (ARDS)
disseminated intravascular coagulation (DIC)
comps of malaria
cerebral malaria: seizures, coma
acute renal failure: blackwater fever, secondary to intravascular haemolysis, mechanism unknown
acute respiratory distress syndrome (ARDS)
hypoglycaemia
disseminated intravascular coagulation (DIC)
cause of conjunctivitis
adenovirus
what does the mantoux test test for
LATENT TB
what can cause a false negative mantoux test
TB
AIDS
Long-term steroid use
Lymphoma
Sarcoidosis
Extremes of age
Fever
Hypoalbuminaemia
Anaemia
when would you use a molecular assay in TB
detects if rifampicin resistant
isolation time for c diff
48 hrs
Toxoplasmosis infection in healthy px
Most infections are asymptomatic. Symptomatic patients usually have a self-limiting infection, often having clinical features resembling infectious mononucleosis (fever, malaise, lymphadenopathy).
dx toxoplasmosis
serology
if immunocomp + cerebral
CT = usually single or multiple ring-enhancing lesions, mass effect may be seen
toxoplasmosis in immunocomp px
Cerebral toxoplasmosis accounts for around 50% of cerebral lesions in patients with HIV
constitutional symptoms, headache, confusion, drowsiness
mx of cerebral toxoplasmosis
pyrimethamine plus sulphadiazine for at least 6 weeks
Disseminated gonococcal infection triad
tenosynovitis, migratory polyarthritis, dermatitis
live attenuated vaccines
BCG
MMR
oral polio
yellow fever
oral typhoid
yellow fever presentation
sudden onset of high fever, rigors, nausea & vomiting. Bradycardia may develop. A brief period of remission (THIS IS KEY) is followed by jaundice, haematemesis, oliguria
typhoid features
fever, myalgia, and constipation
what is lassa fever
viral haemorrhagic fever
endemic in West Africa
bacteria to be worries about post splenectomy (may cause sepsis)
encapsulated bacteria
Strep Pneumonia
Haemophilus influenzae
Neisseria Meningitiditis
whats sld px w hyposplenism be vaccinated against
pneumococcal, Haemophilus type B and meningococcus type C
typhoid fever presentation (Salmonella typhi)
initially systemic upset
relative bradycardia
abdominal pain, distension
constipation: although Salmonella is a recognised cause of diarrhoea, constipation is more common in typhoid
rose spots: present on the trunk in 40% of patients, and are more common in paratyphoid
key for Leptospirosis
spread by rat urine
- commonly seen in questions referring to sewage workers, farmers, vets or people who work in an abattoir
specific sign for gas gangrene
crepitus on palpation
most common infective cause of diarrhoea in patients with HIV
Cryptosporidium parvum - protozoa
Most common organism found in central line infections
Staphylococcus epidermidis
abx to give to uti if breastfeeding
Trimethoprim - present in mil but fine short term
Nitrofurantoin should be avoided when breastfeeding - small amounts in milk but can cause haemolysis in G6PD infants.
what bacteria is acute food poisoning most commonly caused by
Staphylococcus aureus, Bacillus cereus or Clostridium perfringens
what does dx of kaposi’s sarcoma suggest + how may it present
HIV infection
Raised purple lesions
