Herpes Flashcards
Give the names of the 5 human herpesviruses.
1 and 2: Herpes simplex
3: Varicella zoster
4: Epstein-Barr virus
5. Cytomegalovirus
How is VZV transmitted?
Respiratory droplets.
How long is the incubation period for VZV?
14-21 days
What is the pathophysiology of chicken pox and shingles?
- VZV invades the respiratory mucosa
- replicates in lymph nodes.
- disseminates via mononuclear cells
- Infects skin epithelial cells.
- This leads to virus containing vesicles, aka chicken pox.
- Remains dormant in sensory nerve roots.
- Dermatomal reactivation is shingles.
Describe the prodrome of chicken pox.
Prodrome 1-2 days: fever, malaise, headache, abdo pain. Followed by rash.
Describe the rash in chicken pox.
Pruritic, erythematous macules which form vesicles, crust in about 48 hours.
When is chicken pox most contagious?
2 days-RASH+5 days (until lesions have scabbed).
Give 3 complications of chicken pox
In immunocompromised: Encephalitis (causes cerebellar ataxia), VZV pneumonia, DIC, pericarditis.
Describe the presentation and course of shingles.
- Painful, hyperaesthetic area
- Macular rash
- Vesicular rash
Dermatomal distribution.
Give 3 complications of shingles
If immunosuppresed, can cause disseminated infection
Chicken pox risk in non-immune contacts
Host-herpetic neuralgia
Ramsay Hunt syndrome
When is shingles infectious?
Until lesions have scabbed
How is chicken pox/shingles diagnosed?
Clinical diagnosis unless immunosuppressed:
Viral PCR
Culture
Immunofluorescence
How is uncomplicated chicken pox/shingles treated?
Oral aciclovir, ideally within 48 hours of rash.
How is complicated chicken pox/ shingles treated?
IV aciclovir. (complicated = pregnant/child/immunosuppressed/severe)
Who is offered VZV vaccination in the UK?
70-year olds, to prevent shingles reactivation.
