VIII- Viral SSTI Flashcards
cutaneous warts etiology
from HPV
-can be common (verruca valgaris), plantar (verruca plantaris), flat (verruca plana on face)
transmit: direct contact with wart or contam surface thru an abrasion
HPV 1 oral
cutaneous warts cytology
hyperkeratotic, painless, exophytic
-koilocytes may be found
-common warts will be in groups usually @hands, elbows, knees
-thickening of skin layers from proliferation induction by blocking p53 and E7
molluscum contagiosum lesion etiology
molluscum contagiosum virus
transmit: direct contact with lesions, sexual, fomites
molluscum contagiosum lesions cytology
painless, pearly, umbilicated (looks like has belly button) nodules
-large eosinophilic cytoplasmic inclusions aka molluscum bodies
HPV life cycle
latent (dormant in ganglion)
lytic (active infection when virus replicates in epithelial tissue)
-reactivation correlated to stressors
virions form in suprabasal layer of skin
viruses of skin ulcers
HSV
viruses of purulent lesions
VZV
skin disease of HSV
primary infection = herpetic gingivostomatitis so lesions outside mouth and in palate
reactivation = herpes labialis aka cold sores
skin disease of varicella zoster virus
chickenpox
rash/lesions at trunk, face, scalp + fever
-vesicles>pustules>scabs in ‘crops of lesions’ so can see all 3 forms in one area
-can complicate to bacterial infection of lesions or pneumonia, neonatal disease
a herpes virus
vaccination of chicken pox
2 doses of live attenuated
-grown in tissue culture
-to prevent primary infection so given to kids
-if can’t have live vaccine then passive immunization (prophylatic)
vaccination of shingles
to protect from reactivation so for 50+
-recombinant zoster vaccine (SHINGRIX) of viral gE protein
-used to have live attenuated but no longer used
common warts HPV
HPV 2, 3, 10
plantar warts HPV
HPV 1, 4
herpes stromal keratitis
from HSV in the eye
-primary infection = conjunctivitis
-recurrent disease = corneal opacity from scar tissue, see dendritic lesions
herpes simplex encephalitis prez
altered consciousness + hallucinations + ansomia + bizarre behavior
herpetic whitlow
lesions from HSV on digits so either fingers or toes (like cold sores)
eczema herpeticum
people with eczema at inc risk for widespread lesions
herpes simplex gladiatorum
specifically in wrestlers
-skin to skin spread during matches
herpes antiviral mechanism
inhibit DNA polymerase by phosphoylating thymidine kinase
-acyclovir
herpes zoster
shingles
reactivation of VZV in elderly or immunosup
-feels like paresthesia (needles/pins) > vesicular lesions unilateral + fever + malaise
-can complicate to postherpetic neuralgia: severe pain at site of lesion for months
diagnosing VZV
tzanck smear will be pos in herpes virus infections
-HSV pos too
smallpox lesions
@mouth and extremities (palms, soles) CENTRIFUGAL
-deeply set into skin (bb pelet)
-synchronous evolution from papule to ulcer that scabs, considered contagious until all scabs gone
-variola virus
chicken pox is centripetal
smallpox vaccine
live strain of vaccinia virus (poxvirus family) NOT attenuated or variola
-routine vaccination stopped in 1972
-some adverse/fatal effects like eczema vaccinatum
-also use for postexposure prophylaxis
roseola infantum
high fever for few days > maculopapular rash
-from HHV6 or 7 that reps in T/B cells and oral pharynx, latent in T cells (6)
5th disease/erythema infectiousum
fever + rash starting on cheeks > lace like pattern
-slap cheek syndrome bc cheeks are red
no vaccine
from B19 parvovirus that grows within hematopoietic cells in bone marrow
german measles
maculopapular rash starting at face then downward
-fainter than measles and not coalesce (more patchy)
-fever is more low grade than measles
-associated with arthralgia and arthritis
rubella virus
measles prez
- fever + 3 C’s (cough, coryza, conjuctivits) + koplik spots ‘grains of sand surrounded by red halo’
- maculopapular rash starts at hairline downward
- other symps like anorexia, diarrhea, lymphadenopathy
measles prevention
measles resistance if: documented 2 doses live vaccine, lab evidence of immunity, physician diagnosed measles, birth before 1957
passive immunopprophylaxis if susceptible
congenital rubella syndrome
infection during first trimester of preg = deafness, cataracts, glaucoma, heart dz, pigmentary retinopathy
-can show purpura, h/smegaly, jaundice
respiratory transmission
measles virus
-forms syncitia (giant multinuc cells)
-very contagious bc infectious for up to 2 hours on fomites and air, respiratory spread- no direct contact needed
complications of measles
diarrhea
otitis media
pneumonia
some encephalitis, seizures, death
measles vaccine
2 doses of live attenuated in chick embyro fibroblasts > subcut injection
-combine with MMR or MMRV
rubella vaccine
live attenuated grown in tissue culture
-in MMR/V
-major objective is to prevent congenital rubella syndrome
other manifestations of B19 parvovirus
- aplastic crisis
- arthralgia, arthritis
- pregnancy, hydrops fetalis, CHF, anemia
