chicken pox Flashcards
what is chicken pox caused by?
- VZV
- commonly occurs in outbreaks during winter and spring
when can chicken pox cause complications?
- immunocompromised
- old age
- malignancy
- dangerous to foetus in pregnancy and can cause severe LRTI to mother
what is abnormal presentation of chicken pox that might make you think someone is immunocompromised ?
- lasting weeks,
- LRTI
- large bleeding vesicles
- lasting a long time
- DIC
how does the virus enter the host?
how long is the incubation period between exposure and rash?
where do the vesicles tend to appear?
What is the common pattern of rash?
- respiratory tract, viraemia occurs 4 days later
- 10-21 days
- head, neck and trunk
- papule, vesicles, pustules (fever), scabs
- vulval lesions can occur in females
how is diagnosis made?
- on a clinical basis, but PCR can be made
how is it normally managed if no complications?
- encourage fluid intake
- paracetamol analgesia
- antihistamines and emollients
how is chicken pox managed in immunocompromised?
- high dose steroids
- IV acyclovir if new lesions after 8 days
what kind of complications may you get?
- viral pneumonia
- encephalitis (ataxia 1 week post rash)
- secondary bacterial skin infection
- conjunctival lesions
- foetal varicella syndrome
if infected with chicken pox in pregnancy what can the outcome be?
what timing of infection in mother might indicate a bad prognosis for the child?
- prematurity and 30% risk of death from severe pneumonia or fulminant hepatitis
- rash 1 week before or up to 2 days after birth , risk of neonatal chickenpox
what is the problem with perinatal chicken pox in mother?
how should this be treated?
- virus transmitted through placenta, but antibody not
- Ig and Acyclovir
how can transmission be prevented?
- avoid contact with neonates, pregnant women and immunocompromised until the spots are crusted over
- (usually after 5/6 days)
- can give vaccine but rarely happens
