Varicella zoster virus Flashcards
Zoster is caused by
reactivation of VZV
dermatoses most comm affected
TCLs
Thoracic 55
Cranial 20 (single most common nerve involved- trigeminal nerve most inv)
Lumbar 15
Sacral 5
total duration if eruption
2-3 wks younger
>6 weeks elderly - scarring
Disseminated herpes zoster. how many lesions
more than 20 lesions outside the affected dermatome.
tx disseminated zoster
IV acyclovir may be changed to oral antibiral ones visceral involvement has been excluded and atleast 2-3 days of IV tx.
ophthalmic zoster what cranial nerve?
ophthalmic division ir 5th cranial nerve.
if external division of the nasocicialry branch is affexted what sign is seen
Vesicles in tge side and tip of the nose ( Hutchinson sign) tge eye is involved 76% if time compared w 34% when not incolved
ocular involvement in zoster is in what form
uveitis (92) abs keratitis 50
results frkm inv if facial and auditory nerves by VZV.
Ramsay hunt sundrome (herpes zoster oticus)
tx zoster
antiviral tx cornerstone if tx.
l
Vala 1000mg and famciclov 500 ng 3x a day.
Acyclovir 800 mg 5x a day
tx for disseminated, opthalmic zoster or ramsay hunt- those failing iral tx shiudl recieve
IV ACYCLOVIR 10 mg/kg 3x a day adj for renal func
mortality rate in pxs w zoster who have undergone bmt
5%
Vzv igg serostatus is determined before transplant.
zoster test of choice
PCR
H:
vesicles are intraepidermal
sides of vesicles are large swollen cells called balloon cells.
acidophilic inclusion bodies
multinucleated kerstinocytes
nuclear molding
peripheral condensation of the nucleoplasm are characteristic and confirmatory.
inflammatory and degenerative changes are noted on posterior root ganglia and dorsal nerve root of affected nerve.
differentiate herpes simplex and herpes zoster diagnostic modality
DFA
pxs taking antiviral meds must stop taking it for ho many days before and after immunization
stop 24 hrs before immunizatioj and not take then 14 days agter immunization
preferred vaccine for shjngles
Shingrix. for 50 yo and above
drug that sloghtly inc risk of zoster
Statin
lifetime risk of dev zoster is .. for more than 80 yo.
under 45 yo- annual incidence less than 1 in 1000z
older than 75- more than 4x greater.
white persons older than 80- 10-30%
women have higher risk
in HIV pxs/ annual risk for vzv
3%
high risk also immunosuppressed and hema malignancy.
mortality rate in pxs w zoster who have undergone BMT is
5%
VZV IGG serostatus is determined before transplant. and all seropositice pxs recieve prophylaxis with either acyclovir 800mg 2x a day or Valacyclovir 500mg 2x a day for 1 year or longer if the px is recieving immunosupp tx.
Dx.
same used in varicella.
clinical appearanc eis pften adequate.
In office tzanck smear - rapidly confirm.
PCR or DFA testing is preferred to viral culture. bec it is rapid. types the virus and has a higher yield than culture.
PCR- Test of choice. 97% positive.
H
as w herpes simplex the vesicles in zoster are intraepidermal.
sides of the vesicles are large swollen cells called BALLOON CELLS( degenerated cells of the spinous layer)
ACIDOPHILIC INCLUSION BODIES.
MULTINUCLEATED KERATINOCYTES
NUCLEAR MOLDING
PERIPHERAL CONDENSATION OF NUCLEOPLASM
Inflammatory and Degenerative changes are also noted in the posterior root ganglia in the dorsal nerve roots of the affected nerve.
CONFIRMAtory with either HSV OR VZV.
vaccine
Zostavax.
persons taking antiviral meds must stope them 24 hrs before immunization and not take them for 14 days after immunization.
shingrix- preferred vaccine for shingles.
