ID

Question 1

slapped cheek rash

Answer 1

parvovirus

can cause fetal hydrops

asymptomatic
pancytopaenia in immunosuppressed patients
aplastic crises e.g. in sickle-cell disease (parvovirus B19 suppresses erythropoiesis for about a week so aplastic anaemia is rare unless there is a chronic haemolytic anaemia)

Question 2

trypanosomiasis

Answer 2

african sleeping sickness

Trypanosoma chancre - painless subcutaneous nodule at site of infection
intermittent fever
enlargement of posterior cervical lymph nodes
later: central nervous system involvement e.g. somnolence, headaches, mood changes, meningoencephalitis

Management
early disease: IV pentamidine or suramin
later disease or central nervous system involvement: IV melarsoprol

Question 3

lyme disease treatment

Answer 3

doxycycline 14-21 days

Question 4

malaria Rx

Answer 4

Uncomplicated falciparum malaria
strains resistant to chloroquine are prevalent in certain areas of Asia and Africa
the 2010 WHO guidelines recommend artemisinin-based combination therapies (ACTs) as first-line therapy
examples include artemether plus lumefantrine, artesunate plus amodiaquine, artesunate plus mefloquine, artesunate plus sulfadoxine-pyrimethamine, dihydroartemisinin plus piperaquine

Severe falciparum malaria
a parasite counts of more than 2% will usually need parenteral treatment irrespective of clinical state
intravenous artesunate is now recommended by WHO in preference to intravenous quinine
if parasite count > 10% then exchange transfusion should be considered
shock may indicate coexistent bacterial septicaemia - malaria rarely causes haemodynamic collapse

Question 5

viral meningitis low glucose

Answer 5

mumps

Question 6

chlamydia Rx

pregnant vs non pregnant

Answer 6

doxycycline (7 day course) or azithromycin (single dose). The 2009 SIGN guidelines suggest azithromycin should be used first-line due to potentially poor compliance with a 7 day course of doxycycline

if pregnant then azithromycin, erythromycin or amoxicillin may be used.

Question 7

breastfeeding in HIV

Answer 7

no

Question 8

endocarditis with -ve blood cultures

Answer 8

coxiella burnetti

Q fever is caused by Coxiella burnetii, a rickettsia. The source of infection is typically an abattoir, cattle/sheep or it may be inhaled from infected dust

typically prodrome: fever, malaise
causes pyrexia of unknown origin, atypical pneumonia, endocarditis (culture-negative)

Rx - doxycycline

Question 9

Lyme disease Ix

Answer 9

NICE recommend that 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
if this test is positive or equivocal then an immunoblot test for Lyme disease should be done

Question 10

Mycobacterium avium

Answer 10

Prophylaxis
clarithromycin or azithromycin when CD4 is less than 100 cells/mm³

Management
rifampicin + ethambutol + clarithromycin

Question 11

mycobacterium features and diagnosis

Answer 11

Features
fever, sweats
abdominal: pain, diarrhoea
lung: dyspnoea, cough
anaemia
lymphadenopathy
hepatomegaly/deranged LFTs

Diagnosis
blood cultures
bone marrow aspirate

Question 12

Amphotericin B

Used for systemic fungal infections

Answer 12

Binds with ergosterol forming a transmembrane channel that leads to monovalent ion (K+, Na+, H+ and Cl) leakage

Nephrotoxicity, flu-like symptoms, hypokalaemia, hypomagnaseamia

Question 13

primary and secondary syphyllis features

spirochaete Treponema pallidum

Answer 13

Primary features
chancre - painless ulcer at the site of sexual contact
local non-tender lymphadenopathy
often not seen in women (the lesion may be on the cervix)

Secondary features - occurs 6-10 weeks after primary infection
systemic symptoms: fevers, lymphadenopathy
rash on trunk, palms and soles
buccal ‘snail track’ ulcers (30%)
condylomata lata (painless, warty lesions on the genitalia )

Question 14

Therefore, only a small list of Gram-positive rods (bacilli) need to be memorised to categorise all bacteria - mnemonic = ABCD L

Answer 14

Actinomyces
Bacillus anthracis (anthrax)
Clostridium
Diphtheria: Corynebacterium diphtheriae
Listeria monocytogenes

Question 15

diarrhoea after reheating rice

Answer 15

bacillus cereus

Question 16

chlamydia causes which skin condition

Answer 16

Lymphogranuloma venereum (LGV) is caused by Chlamydia trachomatis.

Typically infection comprises of three stages
stage 1: small painless pustule which later forms an ulcer
stage 2: painful inguinal lymphadenopathy
stage 3: proctocolitis

LGV is treated using doxycycline.

Question 17

cellulitis Rx

Answer 17

Flucloxacillin 1st line
Clarithromycin, erythromycin (in pregnancy) or doxycyline is recommended in patients allergic to penicillin.

NICE recommend that patients severe cellulitis should be offered co-amoxiclav, cefuroxime, clindamycin or ceftriaxone.

Question 18

Pneumocystis jiroveci Rx

Answer 18

co-trimoxazole

IV pentamidine in severe cases

Question 19

Lyme disease with disseminated or central nervous system involvement

Answer 19

IV ceftriaxone

Question 20

painful genital ulcers

Answer 20

herpes

consider behcets

Question 21

cerebral toxoplasmosis

Answer 21

ring enhancing lesions on CT

Treatment is usually reserved for those with severe infections or patients who are immunosuppressed
pyrimethamine plus sulphadiazine for at least 6 weeks

Question 22

contact to meningitis

Answer 22

oral ciprofloxacin (or rifampicin)
meningococcal vaccination should be offered to close contacts when serotype results are available, including booster doses to those who had the vaccine in infancy

pneumococcal meningitis, no prophylaxis is generally needed

Question 23

Primaquine

Answer 23

non-falciparum malaria to destroy liver hypnozoites and prevent relapse

Question 24

non falciparum malaria Rx

Answer 24

Treatment
in areas which are known to be chloroquine-sensitive then WHO recommend either an artemisinin-based combination therapy (ACT) or chloroquine
in areas which are known to be chloroquine-resistant an ACT should be used
ACTs should be avoided 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

Question 25

latent tuberculosis Rx

Answer 25

3 months of isoniazid (with pyridoxine) and rifampicin OR 6 months of isoniazid (with pyridoxine)

Question 26

PCP bronchoalveolar lavage

Answer 26

silver stain shows cysts

Question 27

flu like illness → brief remission→ followed by jaundice and haematemesis

Answer 27

Yellow fever Type of viral haemorrhagic fever (also dengue fever, Lassa fever, Ebola). Basics zoonotic infection: spread by Aedes mosquitos incubation period = 2 - 14 days Features may cause mild flu-like illness lasting less than one week classic description involves sudden onset of high fever, rigors, nausea & vomiting. Bradycardia may develop. A brief remission is followed by jaundice, haematemesis, oliguria if severe jaundice, haematemesis may occur Councilman bodies (inclusion bodies) may be seen in the hepatocytes

Question 28

syphillis Ix

Answer 28

``` Serological tests can be divided into: cardiolipin tests (not treponeme specific) treponemal-specific antibody tests ``` Cardiolipin tests syphilis infection leads to the production of non-specific antibodies that react to cardiolipin examples include VDRL (Venereal Disease Research Laboratory) & RPR (rapid plasma reagin) insensitive in late syphilis becomes negative after treatment Treponemal specific antibody tests example: TPHA (Treponema pallidum HaemAgglutination test) remains positive after treatment

Question 29

tetanus vaccine

Answer 29

Intramuscular human tetanus immunoglobulin should be given to patients with high-risk wounds (e.g. Compound fractures, delayed surgical intervention, significant degree of devitalised tissue) irrespective of whether 5 doses of tetanus vaccine have previously been given If vaccination history is incomplete or unknown then a dose of tetanus vaccine should be given combined with intramuscular human tetanus immunoglobulin for high-risk wounds

Question 30

severe hepatitis in pregnancy

Answer 30

hepatitis E RNA hepevirus spread by the faecal-oral route incubation period: 3-8 weeks common in Central and South-East Asia, North and West Africa, and in Mexico causes a similar disease to hepatitis A, but carries a significant mortality (about 20%) during pregnancy does not cause chronic disease or an increased risk of hepatocellular cancer a vaccine is currently in development*, but is not yet in widespread use

Question 31

widespread demyelination due to infection of oligodendrocytes by JC virus (a polyoma DNA virus) symptoms, subacute onset : behavioural changes, speech, motor, visual impairment CT: single or multiple lesions, no mass effect, don't usually enhance. MRI is better - high-signal demyelinating white matter lesions are seen

Answer 31

progressive multifocal leucoencephalopathy in HIV

Question 32

rabbit bite

Answer 32

Tularaemia is a zoonotic infection involving the microorganism F. tularensis commonly transmitted through lagomorphs such as rabbits, hares and pikas but also in aquatic rodents - beavers and muskrat - and ticks. It can present in a variety of forms. Commonly, it produces an erythematous papulo-ulcerative lesion at the site of the bite with reactive and ulcerating regional lymphadenopathy. It is treated with antibiotics such as doxycycline.

Question 33

EBV malignancies

Answer 33

hodgkins lympoma burkitt's lymphoma nasopharyngael carcinoma

Question 34

Aciclovir MOA

Answer 34

guanosine analog, phosphorylated by thymidine kinase which in turn inhibits the viral DNA polymerase

Question 35

Lassa fever

Answer 35

from rodent excrement no specific sx sometimes viral haemorrhagic fever

Question 36

genital warts Rx

Answer 36

Management topical podophyllum or cryotherapy are commonly used as first-line treatments depending on the location and type of lesion. Multiple, non-keratinised warts are generally best treated with topical agents whereas solitary, keratinised warts respond better to cryotherapy imiquimod is a topical cream which is generally used second line genital warts are often resistant to treatment and recurrence is common although the majority of anogenital infections with HPV clear without intervention within 1-2 years

Question 37

Oseltamivir (Tamiflu)

Answer 37

a neuraminidase inhibitor which prevents new viral particles from being released by infected cells

Question 38

Cat scratch disease

Answer 38

bartonella henselae

Question 39

animal bite most common organism

Answer 39

Pasteurella multocida

Question 40

dengue transmitted by

Answer 40

Aedes aegypti mosquito

Question 41

desaturation on exercise

Answer 41

PCP

Question 42

peritonsillar abscesses can develop

Answer 42

Lemierre's syndrome (thrombophlebitis of the internal jugular vein)- this can present with neck pain and can result in septic pulmonary embolism.

Question 43

group A strep (pyogenes)

Answer 43

erysipelas, impetigo, cellulitis, type 2 necrotizing fasciitis and pharyngitis/tonsillitis immunological reactions can cause rheumatic fever or post-streptococcal glomerulonephritis erythrogenic toxins cause scarlet fever

Question 44

false positive VDRL/RPR (syphillis

Answer 44

``` SLE Tuberculosis Malaria HIV SomeTimes Mistakes Happen ```

Question 45

LP lymphocytes

Answer 45

viral or TB | TB more insidious

Question 46

long incubation, non bloody diarrhoea

Answer 46

giardia Rx metronidazole

Question 47

HIV test

Answer 47

HIV antibody test most common and accurate test usually consists of both a screening ELISA (Enzyme Linked Immuno-Sorbent Assay) test and a confirmatory Western Blot Assay most people develop antibodies to HIV at 4-6 weeks but 99% do by 3 months p24 antigen test usually positive from about 1 week to 3 - 4 weeks after infection with HIV sometimes used as an additional screening test in blood banks

Question 48

URTI + amoxicillin > Rash

Answer 48

?glandular fever

Question 49

severe malaria

Answer 49

parasitaemia >2%

Question 50

Schistosomiasis

Answer 50

swimmer's itch' in patients who have recently returned from Africa. Schistosoma haematobium is a risk factor for squamous cell bladder cancer. frequency haematuria bladder calcification Management single oral dose of praziquantel

Question 51

Chikungunya

Answer 51

flu like Sx joint pain rash

Question 52

genital wart Rx

Answer 52

multiple, non-keratinised warts: topical podophyllum | solitary, keratinised warts: cryotherapy

Question 53

Chagas' disease

Answer 53

Which celebrity is most likely to Chug ass, Tom cruise Trypanosoma cruzi Management treatment is most effective in the acute phase using azole or nitroderivatives such as benznidazole or nifurtimox chronic disease management involves treating the complications e.g., heart failure (95%) are asymptomatic in the acute phase although a chagoma (an erythematous nodule at site of infection) and periorbital oedema are sometimes seen. Chronic Chagas' disease mainly affects the heart and gastrointestinal tract myocarditis may lead to dilated cardiomyopathy (with apical atophy) and arrhythmias gastrointestinal features includes megaoesophagus and megacolon causing dysphagia and constipation

Question 54

Toxocara canis

Answer 54

commonly acquired by ingesting eggs from soil contaminated by dog faeces commonest cause of visceral larva migrans other features: eye granulomas, liver/lung involvement

Question 55

Strongyloides stercoralis

Answer 55

acquired percutaneously (e.g. walking barefoot) causes pruritus and larva currens - this has a similar appearance to cutaneous larva migrans but moves through the skin at a far greater rate abdo pain, diarrhoea, pneumonitis may cause Gram negative septicaemia due carrying of bacteria into bloodstream eosinophilia sometimes seen management: thiabendazole, albendazole. Ivermectin also used, particularly in chronic infections

Question 56

meningococcal meningitis Rx

Answer 56

IV benpen or cefotaxime IV chloramphenicol if penallergic

Question 57

tetracycline (doxy)

Answer 57

photosensitive rash can treat acne vulgaris

Question 58

``` Protease inhibitors (PI) examples: indinavir, nelfinavir, ritonavir, saquinavir ```

Answer 58

side-effects: diabetes, hyperlipidaemia, buffalo hump, central obesity, P450 enzyme inhibition indinavir: renal stones, asymptomatic hyperbilirubinaemia ritonavir: a potent inhibitor of the P450 system

Question 59

Amantadine - MOA

Answer 59

inhibits uncoating (M2 protein) of virus in cell. Also releases dopamine from nerve endings

Question 60

leptospirosis

Answer 60

``` Features fever flu-like symptoms renal failure (seen in 50% of patients) jaundice subconjunctival haemorrhage headache, may herald the onset of meningitis ``` Management high-dose benzylpenicillin or doxycycline

Question 61

Jarisch-Herxheimer reaction

Answer 61

Syphyllis post IM benpen fever, rash, tachycardia after the first dose of antibiotic in contrast to anaphylaxis, there is no wheeze or hypotension it is thought to be due to the release of endotoxins following bacterial death and typically occurs within a few hours of treatment No treatment is needed other than antipyretics if required

Question 62

amoeba Ix

Answer 62

hot stool sample - stops cysts (a stool examined within 15 minutes of passage, or kept warm) is required to make a microscopic diagnosis of intestinal amoebiasis as once cooled Entamoeba histolytic returns to its cystic state and becomes indistinguishable from the non-pathogen Entamoeba dispar

Question 63

gram -ve cocci

Answer 63

Neisseria meningitidis + Neisseria gonorrhoeae, also Moraxella catarrhalis

Question 64

returning malaise and flu like Sx in traveller | raised ALT, throbocytopenia

Answer 64

dengue

Question 65

Ribavirin - MOA

Answer 65

guanosine analog which inhibits inosine monophosphate (IMP) dehydrogenase, interferes with the capping of viral mRNA

Question 66

rapid onset high fever pleuritic chest pain herpes labialis

Answer 66

strep pneumonia