infectious diseases Flashcards
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.
Herpes zoster aka varicella zoster virus
vesicles may appear but they never follow a particular dermatome.
herpes simplex
presence of scabs around the groin or any other fold
tinea inguinales
This appears like a burn. It appears as bullae which eventually burst. It could be generalised.
strep scalded skin syndrome
could sometimes appear as streptococcal scalded skin syndrome, but there are more likely to be pustules.
staph a
drop-like, fir-tree puritic lesion following sore throat
guttate psoriasis
a papulosquamous disorder of unknown aetiology which presents as red-orange plaques. It is a cause of erythroderma.
Pityriasis rubra pilaris
Pityriasis rosea
Pityriasis rosea is of unknown aetiology and is a widespread pink patchy rash that appears after a ‘herald patch’.
Causes of erythema multiforme
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).
features of PCP
Several days/weeks of increasing dyspnoea
Dry cough
Marked oxygen desaturation with exercise.
Signs of immunocompromise
Clear CXR
bilaeral crackles
severe exfoliative disease with mucus membran involvement
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).
treatment for samonella typhi
ciprofloxacin
disseminated gonoccal infection
septic arthritis, arthralgia, endocarditis, meningitis, and fevers.
signs of epididymitis
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.
Timing of BCs in IE
Draw three samples of blood from different venepuncture sites with the first separated from the last by at least one hour over 24 hours
Diarrhoea Abdominal pain Flatulence Nausea Anorexia, and Weight loss. Travel
Giardia lambia
contaminated water
rx:metronidazole
scabies treatment
permethrin cream, topical benzyl benzoate, and malathion
Treated gonorrhoes, ongoing urethritis
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.
ventilator associated pnemonia
haemophilis influenza (gram -ve bacilli) strptotrphmona maltophilia, rare cause
urethritis, conjunctivitis, arthritis
Reactive arthritis
Disseminated gonoccoal infection, gram negative intracellular diplococci
treat with ceftriaxone and azithromycin
neutrophillic CSF/ meningitis and immunocompromise
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)
Marker of hepatitis B infection
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
treatment for c diff
oral metronidazole, oral vanc is an alternative
side effects of AZT
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.
endemic in sheep farming regions. Asymptomatic, calcified cystic lesions in the liver
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?
Cyanosis, pleuritic chest pain and haemoptysis are common.
In adults with pneumonitis, treatment with aciclovir is warranted.
meningitis prophylaxis
ciprofloxacin
green colouration of the colonies
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.
treatment of CAP
low curb: doxycyline
high curb: IV co-amox and clari
pen allergy: cef and clari or teic
pnemonia, hemolytic anemia, erythema multiforme
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.
Immunocompromised (HIV) and meningitis
India ink stain of CSF that shows typical yeast-like forms
cryptococcus
neurology (seizures, meningism), fever, background of sinusitis, ring enhancing lesion on CT
bacterial CSF
pyogenic brain abscess
other ring enhancing lesions:
- toxoplasmosis (also presents like EBV)
- TB/histoplasmosis (also has chest symptoms)
live vaccine in immunocompromised
yellow fever