Infection

Question 1

causes of meningitis

Answer 1

infection
intrathecal drug
malignant cells
blood (following subarachnoid haemorrhage)

Question 2

how do microorganisms reach the meninges in meningitis

Answer 2

ears
nasopharynx
cranial injury
blood stream

Question 3

common bacterial organisms causing meningitis

Answer 3

neisseria meningitidis

streptococcus pneumoniae

Question 4

clinical features bacterial meningitis

Answer 4

headache
neck stiffness
fever
all develop over minutes to hours
photophobia and vomiting
kernig’s sign - severe stiffness of the hamstrings = inability to straighten
in meningococcal septicaemia = non-blanching petechial & purpuric skin rash and signs of shock

Question 5

clinical features viral meningitis

Answer 5

benign self-limiting condition lasting for about 4-10d

no serious sequelae

Question 6

non blanching petechial or purpuric skin rash = what? what needs to happen asap?

Answer 6

meningococcal infection
immediate (before hosp transfer) rx w benzylpenicillin or cefotaxime
lumbar puncture should NOT be performed if meningococcal sepsis is suspected because coning of the cerebellar tonsils will follow

Question 7

investigations meningitis

Answer 7

head CT

lumbar puncture - urgent CSF microscopy, WCC and analysis for protein and glucose

Question 8

normal CSF appearance

Answer 8

clear

Question 9

bacterial CSF appearance

Answer 9

turbid (cloudy) / purulent (pus)

Question 10

viral CSF appearance

Answer 10

clear / turbid (cloudy)

Question 11

TB CSF appearance

Answer 11

turbid / viscous

Question 12

rx bacterial meningitis

Answer 12

cefotaxim initially
add ampicillin or co-trimoxazole if risk of listeria
subsequent Abx dependent on organism in CSF
IV fluids and inotropes are given if there is also septicaemia

Question 13

what is given to ppl who were in contact w meningitis person

Answer 13

oral rifampicin or ciprofloxacin

Question 14

encephalitis

Answer 14

inflammation of the brain parenchyma

unlike meningitis, cerebral function is abnormal w altered mental state

Question 15

encephalitis caused by?

Answer 15

mainly viruses

Question 16

encephalitis mainly affects

Answer 16

MSM
IVDU
HIV
where opportunistic organisms are causes

Question 17

organisms that cause acute viral encephalitis

Answer 17

herpes simplex virus
ECHO - enteric cytopathic human orphan
Coxsackie and mumps

Question 18

clinical features acute viral encephalitis

Answer 18

mild self limiting illness with fever, headache and drowsiness
less commonly it’s severe with focal signs eg hemiparesis, dysphagia, seizure and coma

Question 19

investigations acute viral encephalitis

Answer 19

CT and MRI shows areas of oedema in temporal lobes
CSF analysis shows inc in mononuclear cells and protein
viral serology of blood and CSF

Question 20

rx acute viral encephalitis

Answer 20

suspected herpes simplex encephalitis is immediately treated with iv aciclovir - antiviral
if pt in coma prognosis = poor

Question 21

varicella zoster virus cuases

Answer 21

chicken pox primarily and shingles after primary infec

Question 22

clinical features varicella

Answer 22

varicella = chickenpox
incubation 14-21d
fever, headache, malaise
rash on face, scalp, trunk = macules initially, develops to papules and vesicles which heal crusting

Question 23

investigations varicella

Answer 23

diagnosis clinical

confirmed by detection of viral DNA in vesicular fluid by PCR

Question 24

management varicella

Answer 24

healthy children = no rx
anyone >16yo = aciclovir
preg women = zoster-immune immunoglobulin and aciclovir

Question 25

herpes zoster

Answer 25

= shingles
remains dormant in dorsal root ganglia and or cranial nerve ganglia
reactivation = shingles

Question 26

clinical features herpes zoster

Answer 26

pain and tingling in a dermatomal distribution precede rash by a few days
rash = papules and vesicles in same dermatome
lower thoracic dermatomes and ophthalmic div of trigem = common sites

Question 27

rx herpes zoster

main complication of herpes zoster

Answer 27

oral aciclovir, valaciclovir or famciclovir asap

main complication = post herpetic neuralgia , avoided by prompt rx