herpes zoster Flashcards
patho of herpes zoster
reactivation of varicella zoster virus
dormant in dorsal root ganglia after acute phase of chickenpox
reactivated as immunity to VZV decreases with age/immunosuppression
travels along nerves to skin- causing pain that precedes distinctive HZ rash
presentation
skin sensitivity i.e. pain, burning, itching on dermatome
HA, fever, malaise during prodromal period
rash appears 2-3 days after skin sensitivity (3 wks prior)
unilateral, red, maculopapular
along dermatome
eruption of vesicle of uniform size, lesion erupt, blister or crust 7-10 days, healing takes 2-4 weeks
management
acute pain controlled, speed healing of lesions, prevent complications, start with antiviral
if immunocompetent pt with HZ get tx if…
> 50YO, mod-sev pain, mod- sev rash, non- truncal involvement
tx with
1)nucleoside analogues
and steroids
nucleoside analogues
*start within 72 hrs of rash- reduce viral shedding and inhibits replication of virus
Acyclovir (Zovirax) 800mg PO 5x daily for 7 to 10 days
Used to be cheapest
Famciclovir (Famvir) 500mg PO 3x daily for 7 days
Prodrug - higher antiviral activity-less frequent dosing
Valacyclovir 1000mg PO 3x daily for 7 days
Prodrug - higher antiviral activity -less frequent dosing than Acyclovir
generic now available - BETTER CHOICE!
steroids
used in combo with nucleoside analogues to decrease pain intensity, not reduce PHN incidence, no for adults due to SE
pain management
NSAID to mild to mod pain
opioids low dose for mod-sev
gabapentin, pregabalin, or tca’s for neuropathic pain
regular dosing better than prn
acyclovir
800mg PO x5 days for 7-10 days - cheapest
famciclovir (famvir)
500mg PO x 4 days for 7 days- prodrug- less dosing needed
valacyclovir
1000mg PO TID for 7 days- progdrug less dosing needed
