Varicella zoster Flashcards
What two infections does varicella zoster virus cause?
1) chicken pox
2) shingles
How does chicken pox present?
widespread, erythematous, raised, vesicular, blistering lesions that start on the trunk or face and spread outwards, affecting the whole body within 2-5 days
How can you tell when a chicken pox patient is no longer contagious?
all the lesions have scabbed/ crusted over
Give 3 systemic symptoms associated with varicella zoster virus:
1) fever
2) itch
3) generalised fatigue and malaise
What are the two modes of transmission of chicken pox?
1) direct contact with lesions
2) infected droplets from a cough or sneeze
What is the incubation period for chicken box?
10 days to 3 weeks
Give 5 complications of chicken pox:
1) pneumonia
2) conjunctival lesions
3) encephalitis (presents with ataxia)
4) dehydration
5) bacterial superinfection
What is a superinfection?
an infection superimposed by a previous one
Name two structures where varicella zoster virus can lie dormant after chicken pox infection:
1) sensory dorsal root ganglion cells
2) cranial nerves
What is congenital varicella syndrome?
a developmental condition caused by a mother contracting chicken pox before 28 weeks gestation
How is chicken pox at the time of delivery (high risk of life-threatening neonatal infection) treated?
varicella zoster immunoglobulins and aciclovir
What treatment is given for chicken pox/ shingles patients who are immunocompromised or at risk of complications?
aciclovir
What is the mechanism of aciclovir?
guanasine analogue
Name two treatments for the itch in chicken pox:
1) calamine lotion
2) chlorphenamine
What is shingles?
a varicella-zoster infection of an individual nerve and the associated dermatome
Give 3 risk factors for shingles
1) female sex
2) immunocompromised e.g. HIV
3) rheumatoid arthritis
How does shingles present?
unilateral vesicular rash in the affected dermatome
In which range of dermatome does shingles most commonly affect?
T1-L2
Who is offered the shingles vaccination in England?
everyone over the age of 60
Name 3 complications of shingles:
1) herpes zoster oticus
2) herpres zoster opthalmus
3) Ramsay Hunt Syndrome
What is herpes zoster oticus?
VZV infection of the facial nerve causing lesions of the ear, facial paralysis and hearing problems
What is herpes zoster opthalmicus?
VZV infection of opthalmic division of the trigeminal nerve causing conjunctivitis, retinitis and glaucoma
What is Ramsay Hunt Syndrome?
acute peripheral facial neuropathy that follows shingles causing hearing loss and facial paralysis
