Herpes Zoster Flashcards
Varicella zoster incubation time
10-21 days
Primary viremia
Respiratory route –> replication in nasopharynx–> seeding of lymph and RE
Infected T cells spread to lymph nodes and reticulo endothelial system (spleen n liver)
Type of skin lesions for chickenpox
Vesicles on epidermis and dermis
Ballooning
Multinucleated giant cells
Eosinophilic intranuclear inclusions
Tzanck smear
Used scrapings and stain w wright giemsa stain
Shows intranuclear inclusions w multinucleated giant cells
Replaced with direct fluorescent antibody test
Secondary viremia chickenpox
After multiplication in RE system
Causes diffuse and scattered skin lesions in form of vesicle
Vesicles erupt on skin
Vesicles later become cloudy due to degenerated cells and leukocytes etc
Chicken pox epidemiology
90% attack rate
Ppl are infectious 48hrs prior to first vesicle and until vesicles have crusted
Vesicle formation 4-5days
Can get bacterial infection of rash is the most common complication
Most serious complication is pneumonia
Herpes zoster shingles
Latent chicken pox establishes in dorsal root ganglion
Shingles reactivates with T3-L3 most frequently involved
We get this when our vzv Tcells have dropped under threshold (they decline with age)
Getting a zoster vaccine prevents tcell droppage
Postherpetic neuralgia
Severe debilitating pain due to vesicular eruption within a dermatome
Zoster ophthalmicus
Involvement of ophthalmic branch in shingles
Zoster pseudodendrites
Onset is 11month after herpes ophthalmicus
Dendrites are rounded terminal bulbs
They are seen 1-2 weeks after infx
Complications of herpes zoster
Postherpetic neuralgia
Herpes ophthalmicus - can cause blindness in absence of antiviral therapy
Vasculopathy -damage to blood vessels
Oka vaccine
2 doses recommended
12-15mo and 4-6yrs
Attenuated live virus
Zostsvax
Attenuated vaccine that is 18x higher virus concentration
Given to adults over 50
Should have prior immunity to chickenpox
Lab diagnosis
Isolation of culture
Elisa test for detection
Or pcr
4fold increase in antibody count is indicative of virus
