infectious diseases Flashcards

1
Q

usually has a prodrome pain before the vesicles appear. It usually follows a particular dermatome but in immune suppression the disease may affect more than one dermatome.

A

Herpes zoster aka varicella zoster virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

vesicles may appear but they never follow a particular dermatome.

A

herpes simplex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

presence of scabs around the groin or any other fold

A

tinea inguinales

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

This appears like a burn. It appears as bullae which eventually burst. It could be generalised.

A

strep scalded skin syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

could sometimes appear as streptococcal scalded skin syndrome, but there are more likely to be pustules.

A

staph a

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

drop-like, fir-tree puritic lesion following sore throat

A

guttate psoriasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

a papulosquamous disorder of unknown aetiology which presents as red-orange plaques. It is a cause of erythroderma.

A

Pityriasis rubra pilaris

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Pityriasis rosea

A

Pityriasis rosea is of unknown aetiology and is a widespread pink patchy rash that appears after a ‘herald patch’.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Causes of erythema multiforme

A

Herpes simplex virus infection is the commonest cause. Other common causes include infection with Mycoplasma and Streptococci.

EM may also:

Be idiopathic
Be drug-induced (sulfonamides, sulphonylureas, barbiturates)
Occur in systemic diseases (SLE, inflammatory bowel disease, malignancy).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

features of PCP

A

Several days/weeks of increasing dyspnoea
Dry cough
Marked oxygen desaturation with exercise.

Signs of immunocompromise
Clear CXR
bilaeral crackles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

severe exfoliative disease with mucus membran involvement

A

TEN is a severe mucocutaneous exfoliative disease with an uncertain pathogenesis and a high mortality rate.

It is difficult to say whether it is another variant of Stevens-Johnson syndrome and treatment of both are similar.

It is often idiopathic but may be associated with:

Viral infections
Leukaemia
Lymphoma, and
Drugs (in particular sulphonamides and anticonvulsants).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

treatment for samonella typhi

A

ciprofloxacin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

disseminated gonoccal infection

A

septic arthritis, arthralgia, endocarditis, meningitis, and fevers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

signs of epididymitis

A

recurrent UTIs

The presence of long term catheters, underlying urinary tract pathology or recent instrumentation are risk factors for epididymitis.

The most common pathogens in men over the age of 35 are coliforms and Pseudomonas.

immediate management is to commence empirical antibiotics which cover Gram positive and negative organisms while awaiting urinary cultures, scrotal elevation, bed rest, and analgesia.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Timing of BCs in IE

A

Draw three samples of blood from different venepuncture sites with the first separated from the last by at least one hour over 24 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q
Diarrhoea
Abdominal pain
Flatulence
Nausea
Anorexia, and
Weight loss.
Travel
A

Giardia lambia
contaminated water
rx:metronidazole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

scabies treatment

A

permethrin cream, topical benzyl benzoate, and malathion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Treated gonorrhoes, ongoing urethritis

A

treat for chlamydua trachomatis/non-specific urethitis

Gonorrhoea is one of the commonest reported STDs in both men and women. In men the symptoms manifest as urethritis and in women cervicitis or urethritis. gram negative intracellular Diplococci

More commonly patients present with co-infection with Chlamydia trachomatis, requiring treatment with either pencillin (ceftriaxone 250mg IM) doxycycline or erythromycin for 7-14 days.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

ventilator associated pnemonia

A
haemophilis influenza (gram -ve bacilli)
strptotrphmona maltophilia, rare cause
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

urethritis, conjunctivitis, arthritis

A

Reactive arthritis

Disseminated gonoccoal infection, gram negative intracellular diplococci
treat with ceftriaxone and azithromycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

neutrophillic CSF/ meningitis and immunocompromise

A

Bacterial infections such as listeria monocytogenes
Treat with ampicillin and genatmicin

Neutrophils (polymorphonuclear, leukocytes containing granules that are released during infection e.g. neutrophils, basphils, eosinophils - granulocytes) presdominated in CSF of bacterial meningitis. However TB and gunal lymphocytic (t/B cells predominate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Marker of hepatitis B infection

A

Anti HBc is present throughout infection

Anti HBc IgM antiboody : acute infectoin

Anti HBc IgG and anti-HBs = recovering from infection

Anti HBc and HBsAg = chronic infection

HBe antigen is a marker of infectivity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

treatment for c diff

A

oral metronidazole, oral vanc is an alternative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

side effects of AZT

A

bone marrow suppresion causing macrocytic anemia

Other side-effects of zidovudine include:

Myalgia
Myopathy
Myositis
Pancytopenia, and
Lactic acidosis.
Blue discolouration of the nails is a rare side-effect.

Macrocytosis is a typical finding in patients on AZT and can be used as a parameter to monitor adherence to therapy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

endemic in sheep farming regions. Asymptomatic, calcified cystic lesions in the liver

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Varicella pneumonia occurs in up to 20% of adults with chickenpox, appearing three to five days into the course of the illness. In adults with pneumonitis, treatment with aciclovir is warranted. what are the symptoms?

A

Cyanosis, pleuritic chest pain and haemoptysis are common.

In adults with pneumonitis, treatment with aciclovir is warranted.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

meningitis prophylaxis

A

ciprofloxacin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

green colouration of the colonies

A

psudomonas aerginosa

production of the pigment pyocyanin.

consistent with a diagnosis of cystic fibrosis; bronchiectasis associated with CF frequently results in recurrent infections with Pseudomonas.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

treatment of CAP

A

low curb: doxycyline

high curb: IV co-amox and clari
pen allergy: cef and clari or teic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

pnemonia, hemolytic anemia, erythema multiforme

A

mycoplasma pneumonia

Extrapulmonary manifestations of Mycoplasma occur in up to 10% of cases of Mycoplasma pneumonia.
These include:
	• Haemolytic anaemia
	• Renal failure
	• Hepatitis
	• Myocarditis
	• Meningism and meningitis
	• Transverse myelitis, and
Cerebellar ataxia.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Immunocompromised (HIV) and meningitis

India ink stain of CSF that shows typical yeast-like forms

A

cryptococcus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

neurology (seizures, meningism), fever, background of sinusitis, ring enhancing lesion on CT
bacterial CSF

A

pyogenic brain abscess

other ring enhancing lesions:

  • toxoplasmosis (also presents like EBV)
  • TB/histoplasmosis (also has chest symptoms)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

live vaccine in immunocompromised

A

yellow fever

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Clue cells on saline wet mount

A

BV

35
Q

atrophic vaginosis are characterised by dyspareunia and inflammation

A

Tichomoniasis

36
Q

what is Enterobius vermicularis

A

threadword
Transmission is by the faeco-oral route and intense anal pruritus is the predominant symptom. Treatment is with mebendazole.

37
Q

what is Hymenolepis nana

A

rodent cestode parasite that can be transmitted to humans and usually affects children. Abdominal pain, anorexia, diarrhoea, pruritus ani and urticaria are the most frequent symptoms. Eosinophilia may be present in heavy infestations. Treatment is with praziquantel.

38
Q

what is ecchonus granulosus

A

responsible for hyatid

39
Q

what is trichuriasis

A

Trichuriasis is commoner in malnourished populations; symptoms are minimal but may result in growth retardation in children. Heavy burdens of infection may be associated with bloody diarrhoea; it is associated with rectal prolapse. Treatment is with mebendazole.

40
Q

Haemophilus ducreyi and presents with painful lymphadeonapthy and erythematous papules.

A

chancroid

Gram negative rod

pustules breakdown to haemorrhagic ulcers

41
Q

single painless ulcer and inguinal lymphadenopathy

A

lymphogranuloma venereum however LGV initially presents as a single painless ulcer with secondary infection occurring two to six weeks later.

42
Q

multiple indolent painful ulcer

A

Granuloma inguinale is caused by Klebsiella granulomatos also know as donoviasis. Regional lymphadenopathy is rare. The incubation period is one to three months.

43
Q

gram positive catalase negative

A

streptococcus

staph is catalase positive

44
Q

What is the basis of methicillin resistance in Staphylococci?

A

the bacteria modify the penicillin-binding protein so that they have a low affinity for beta-lactamase antibiotcis, pseudomonas and enterococcus do the same

45
Q

what is brucella melitensis

A

causes brucellosis

  • fever, arthralgia, abnormal liver function tests, and coccobacilli on blood culture
  • Untreated patients may be symptomatic for months, with localisation of the disease to the brain, genitourinary tract, liver and heart.
  • Treatment is with doxycycline and a second agent such as gentamicin or rifampicin.
46
Q

motile flagellated protozoa, yellow discharg, strawberry cervix

A

trichmonas vaginalis

rx: metronidazole

47
Q

management of neuroschistosomiasis

A

neuroschistosomiasis is secondary to hypersensitivity reactions there is need to use a steroid, in this case prednisolone 1 mg/kg per day.

Praziquantel 60 mg/kg per day for six days is recommend for S. japonicum

48
Q

post oragan transplant, leukopenia, fever, dyspnoea

A

CMV Infection

49
Q

treatment fro staph a IE

A

IV gent and vanc

50
Q

treatment for strep IE

A

IV benpen and gent

51
Q

what is severe PCP and management

A

PO2 < 9

Co-trimoxazole or IV pentamidine/clindamycin with primaquine (if allergic)

and Steroids

52
Q

Treatment for suspected TB meningitis

A

Start ceftriaxone (bacterial meningitis), RIPE and dexamthasone

53
Q

Treatment for varicella zoster in immunocompromised

A

IV aciclovir TDS 10mg/kg

54
Q
e.europe, russia, asia
sore throat, grey membrane on tonsils
cervical lymphadenopathy
neuritis
heart block
A

Diptheria

gram positive

55
Q
necrotic black eschar
painless, non-tender
spread by infected carcasses
marked oedema
GI bleeding
A

Anthra

Bacilus anthracis, gram positive rod

56
Q

Norcardia

A

similar to actinomyces, fungud like
gram +ve rod
sulhur granules
pneumonia and brain abscess in immunocompromised

57
Q

TB meningitis treatment

A

RIPE and dexamethasone

58
Q

actinomyces

A
gram positive rod, fungus like hyphae
sulphur granule masses
spreads through mucosa, forms oral/throat abscesses
abdo mass RIF
multiple sinus tracts
occurs in those with appendicitis

RX: long term penicillin, surgical resection

59
Q

Cryptococcus meningo-encephalitis

A

Cryptococcus meningo-encephalitis. The causative organism is Cryptococcus neoformans, a fungus which causes severe infection in patients with defective cell-mediated immunity.

This is an AIDS-defining illness which typically occurs when the CD4 count is less than or below 100. Symptoms are typically of gradual onset over one to two weeks. Diagnosis is by examination of CSF with India ink. This will demonstrate typical encapsulated yeast forms.

Treatment regimes include the use of IV amphotericin B, to which flucytosine is sometimes added. In certain instances a long course of fluconazole may be used.

60
Q

Trichuris trichiura

A

Trichuris trichiura (whipworm) is a helminth approximately 4 cm in length. Infected patients are largely asymptomatic.

61
Q

hookworms

A

Necator americanus and Ancylostoma duodenale are hookworms (~1 cm in length). The major manifestation of chronic disease is iron-deficiency anaemia.

62
Q

nematode

A

Strongyloides stercoralis is a nematode infection. Symptoms may be cutaneous (pruritus due to invasion by the nematodes), pulmonary (eosinophilic pneumonia due to passage through the lungs) or gastrointestinal (abdominal pain).

63
Q

Ascaris lumbricoides is a large roundworm, growing up to 35 cm in length, and is the most common nematode parasite of humans. Infected patients are often asymptomatic. Symptoms may develop as a result of pneumonitis caused by the worm’s migration through the lungs, obstruction of the gastrointestinal tract or biliary/pancreatic duct obstruction. Piperazine is the treatment of choice in patients presenting with bowel obstruction; mebendazole may be used to treat other infections.

A

Ascaris lumbricoides is a large roundworm, growing up to 35 cm in length, and is the most common nematode parasite of humans. Infected patients are often asymptomatic. Symptoms may develop as a result of pneumonitis caused by the worm’s migration through the lungs, obstruction of the gastrointestinal tract or biliary/pancreatic duct obstruction. Piperazine is the treatment of choice in patients presenting with bowel obstruction; mebendazole may be used to treat other infections.

64
Q

fish-tank granuloma

A

fish-tank granuloma, caused by the atypical mycobacterium, Mycobacterium marinum. It is found in ornamental fish and is commonly seen in individuals who rear fish as a hobby.

65
Q

Cryptococcal meningitis

A

Diagnosis is by demonstration of C. neoformans in the cerebrospinal fluid, shown on an India ink stain: the thick polysaccharide capsule is highlighted around the cell (shown in slide).

Cryptococcal meningitis is an AIDS-defining illness occurring when CD4 less than 50 cells/mm3 and may be associated with a pneumonitis.

Cryptococcus can also cause papular skin lesions that resemble molluscum contagiosum.

The disease is commoner in African populations.

66
Q

weever fish sting

A

The weeverfish (Trachinus vipera) lives in shallow waters around the coast of the United Kingdom.

This small, sandy-coloured fish has sharp dorsal opercular spines that are attached to subcutaneous poison glands. Most stings from the weeverfish occur in the summer months in bare-footed bathers who step on the fish in shallow water, but stings also occur in anglers who attempt to grasp the fish when caught on a line.

The sting of the fish causes intense pain at the site of the wound. The toxin produced by the fish is heat-labile and is denatured at temperatures above 40°C. Treatment of a weeverfish sting should include cleansing of the wound and immersion in hot water (as hot as can be borne), ideally around 45°C.

67
Q

acute rubella serology

A

A positive rubella haemagglutination inhibition (HAI) combined with a negative rubella IgM is consistent with:

Early acute infection with rubella
Previous vaccination, or
Previous rubella infection.
The most important issue to resolve is whether she has acute rubella.

The IgM may take several days to rise and the test should be repeated one to two weeks later.

68
Q

treatment of nuetropenic sepsis with indwelling central line

A

Initial empiric antibiotic therapy for patients with suspected neutropenic sepsis with indwelling central venous access devices includes Tazocin, Gentamicin and Vancomycin.

69
Q

chronic treatment of lithium toxicity

A

Lithium toxicity is more common when renal excretion of lithium is reduced, for example, concomitant use of diuretics or non-steroidal anti-inflammatory drugs (NSAIDs), or dehydration.

Cardiovascular adverse effects are more likely to occur in the presence of underlying cardiac disease.

In acute or chronic toxicity, a lithium level of greater than 4 mmol/L or features of central nervous system toxicity or cardiac instability are indications for haemodialysis.

Whole bowel irrigation should be considered in adults who have ingested a slow release preparation of lithium of greater than 4 g.

70
Q

botulism

A

descending progressive weakness. There is cranial nerve involvement affecting ocular movements, swallowing, and facial musculature. There is also weakness of neck extension and intercostals as evidenced by reduced chest expansion. In addition she complains of autonomic features such as vomiting, abdominal pain and dry mouth.

This combination of signs and symptoms are in keeping with botulism.

Botulism is caused by a neurotoxin produced by Clostridium botulinum (CB). The toxin binds irreversibly to the presynaptic membranes of peripheral neuromuscular and autonomic nerve junctions. Toxin binding blocks acetylcholine release, resulting in weakness, flaccid paralysis, and (often) respiratory arrest.

Botulism can be food-borne or develop from wound infection (the likely source in this woman’s case from intravenous drug injection). Botulism can cause a false positive tensilon test result.

71
Q

HAART regime

A

HAART typically consists of a regime of three or more antiretroviral agents of different classes.

A typical regime consists of two nucleoside analogues (for example, zidovudine [AZT], lamivudine [3TC]) and either a protease inhibitor (for example, nelfinavir, indinavir, ritonavir) or a non-nucleoside reverse transcriptase inhibitor (for example, nevirapine, efavirenz).

Antiretroviral therapies are frequent causes of anaemia in HIV-seropositive patients. Of these, zidovudine (AZT) is the agent that most frequently causes anaemia, usually by bone marrow suppression and patients can become transfusion-dependent in severe cases.

Macrocytosis is a typical finding in patients on AZT and can be used as a parameter to monitor adherence to therapy.

72
Q

Scombroid poisoning

A

Scombroid poisoning is associated with consumption of Scombridae, dark meat fish such as tuna, mackerel and marlin.

The symptoms are due to ingestions of amines, predominantly histamines, produced by bacterial decarboxylation of histidine in fish meat. The most common cause of scombroid poisoning is due to ingestion of spoiled fish following inadequate refrigeration or prolonged time at room temperature. Cooking does not inactivate the toxin/histamines.

The illness is usually self-limiting and the severity is dependent on the amount of fish ingested, that is, symptoms are worse when a large amount of fish is ingested.

Onset is usually 10-30 minutes post-ingestion of the implicated fish but a delayed onset may occur up to two hours.

The symptoms that occur are typically associated with histamine such as

Headache
Dizziness
Abdominal pain
Palpitations
Nausea
Diarrhoea
Urticarial rash
Bronchospasm and
Hypotension or hypertension.
Patients with pre-existing conditions such as bronchial asthma, and those taking isoniazid (a histaminase inhibitor) may be more symptomatic.

Specific treatment is usually unnecessary and most symptoms subside between two and 36 hours. In severe cases, symptoms respond rapidly to antihistamines, for example, chlorpheniramine and intravenous cimetidine by slow intravenous injection over at least five minutes.

73
Q

red cysts on ZN stain stool sample

A

stool: modified Ziehl-Neelsen stain (acid-fast stain) of the stool may reveal the characteristic red cysts of Cryptosporidium

watery diarrhoea
abdominal cramps
fever
in immunocompromised patients the entire gastrointestinal tract may be affected resulting in complications such as sclerosing cholangitis and pancreatitis

74
Q

HIV CNS infections

A
  1. SOLs - toxoplasmosis (multiple ring enhancing lesions), lymphoma (homogenous single lesion)
  2. Enephalitis (HIV, CMV)
  3. meningitis (cryptococcus - also has nerve palsies)
  4. PML - JC virus, periventricular lesions, demyelinating condition, behavioural changes
  5. dementia (AIDS/HIV complex)
75
Q

HVZ and pregnancy

A

if asymptomatic test for antibodies

if -ve, PO aciclovir or immunoglobulins

76
Q

Leptospirosis features

A

spirochaete, spread in faeces contaminated water

Features
the early phase is due to bacteraemia and lasts around a week
may be mild or subclinical
fever
flu-like symptoms
subconjunctival suffusion (redness)/haemorrhage

second immune phase may lead to more severe disease (Weil’s disease)
acute kidney injury (seen in 50% of patients)
hepatitis: jaundice, hepatomegaly
aseptic meningitis

rx: doxy

77
Q

PVL

A

Panton-Valentine Leukocidin is a pore-forming toxin which is produced by staphylococcus aureus. It has an affinity for white blood cells and the endothelium. Clinically PVL will often present with a necrotising pneumonia, characterised by severe bilateral pneumonia with cavitations on X-ray. Often patients presenting will have a history of boils or necrotic skin lesions. As the staphylococcus is easily transmitted there may be a recent family history of similar infections / boils.

Rx: linezolid

78
Q

TB tretament

A

RIPE for 2 months, the RIP for 4 months

isoniazid resistant: RE for 6 months

79
Q

RIPE SEs

A

Drug adverse effects

rifampicin
potent liver enzyme inducer
hepatitis, orange secretions
flu-like symptoms

isoniazid
peripheral neuropathy: prevent with pyridoxine (Vitamin B6)
hepatitis, agranulocytosis
liver enzyme inhibitor

pyrazinamide
hyperuricaemia causing gout
arthralgia, myalgia
hepatitis

ethambutol
optic neuritis: check visual acuity before and during treatment

80
Q

typhus

A

samonella typhi or paratyphus, same features
spread by faecal-oral route

features:

  • systemic sx
  • constipation
  • abdo pain
  • bradycardia
  • rose spots

complications

  • meningitis
  • bowel perf
  • cholecystitis
  • OM

cefotaxime/ceftriaxone

81
Q

ESs of PIs

A

Protease inhibitors (PI)
examples: indinavir, nelfinavir, ritonavir, saquinavir
side-effects: diabetes, hyperlipidaemia, buffalo hump, central obesity, P450 enzyme inhibition
indinavir: renal stones, asymptomatic hyperbilirubinaemia
ritonavir: a potent inhibitor of the P450 system

82
Q

rickettsiae

A

rocky mountain - peripheral to central rash, north america
q fever - pneumonia
tropical scrub typhus - black eshar from tick bite

rx: tetracycline e.g. doxycycline

83
Q

CMV presentations

A

neonatal/congential:
- features include growth retardation, pinpoint petechial ‘blueberry muffin’ skin lesions, microcephaly, sensorineural deafness, encephalitiis (seizures) and hepatosplenomegaly

immunocompetent:
- mononeucleosis: like EBV

immunocompromised e.g. HIV or organ transplant

  • retinitis: cheesy pizza iv ganciclovir
  • meningiti-pneumonitis
  • colitis: CMV colitis with rectal and oesophageal involvement would explain the tenesmus, odynophagia, along with the bloody diarrhoea, abdominal cramps and weight loss.

infected cells have ‘owls eye’ appearance

84
Q

schistosomiasis complications

A

s. haemaboticum: renal/bladder ca
s. mansoni/japonicum: block portal system = cirrhosis and varices

s intercalatum/maekonngi: Gi obstruction