viral infections of the skin (7) Flashcards
where do exogenous infections come from?
- Infection at the site of the lesion
- Breaks in skin integrity: cuts, insect bites, pimples
- Or on mucus membranes
where do endogenous infections come from?
- Disseminated infection
- Spread through blood (viremia) or lymph
- Reactivation from latency: herpes virus (Neurons, lymphocytes)
dfine exanthem
an eruptive disease, infectious rash
define popular
raised discolored patch
if a rash is a dermatitis, is it infectious?
no
define umbilicated. give an example of a rash that is umbilicated
dimple in the center of the postule
molluscum contagiousum
describe the characteristics of the Herpes simplex virus
large, enveloped DNA virus
8 diff species
what is the treatment for the primary HSV-1 infection?
antivirals
oral acyclovir or derivative
what is the name of a the recurrent HSV1 infection?
herpes labialis (cold sores)
what will trigger herpes labialis?
fever, UV, exposures, hormones, stress, physical trauma
what can you do for treatment of recurrent HSV1 infections
can put someone on an antiviral daily, or they can take it when they feel the cold sore coming on
what is herpetic whitlos
primary HSV1 or HSV2 infection of non mucosal sites acquired by direct contact
what population of ppl is herpetic whitlos infection seen on?
used to be seen on dentists and dental hygienist, not any more bc gloves but can be seen on wrestlers
what is the treatment for herpetic whitlos?
acyclovir and derivatives
describe the rash seen in HSV2 primary infection
Extensive vesicular, pustular or erythematous lesions on penis, labia, anus
describe the prodrome phase of recurrent genital herpes
itching, tingling at site of lesion before outbreak
where does HSV3 (varicella zoster) infections take latency?
dorsal root ganglia
how is varicella transmitted?
aerosol
describe the rash in varicella
“dew drops on rose petals”. Few to hundreds on face and trunk
Lesions are itchy, vesicular from scabs that may scar
can you transmit zoster?
no, you would give a naive person varicella
describe the rash in shingles
Vesicular lesions are extremely painful and pruritic
list some of the complications of shingles
keratitis, retinitis, bell’s palsy, postherpetic neuralgia
what is the name of the vaccine for varicella? who should get it
varivax.
ppl age 1-60
what is the vaccine for zoster? who should get it
zostavax
greater than 50
what cells does EBV infect? what disease does it cause
infects B cells
mononucleosis
in immunosupressed, how can recurrent EBV infection present? describe this infection
oral hairy leukoplakia
epithelial overgrowth
Nonpainful hairy or feathery lesions on the tongue or buccal mucosa
what are 2 major differences between EBV and CMV
EBV: sore throat
CMV: petechial rash
what herpes viruses cause roseola? what cells are infected?
HHV6b and HHV7 infects CD4 T cells
how is roseola transmitted
by salvia. RASH IS NOT CONTAGIOUS
what can often happen when a child comes into the doc office with roseola?
many infants mistakenly given antibodies for suspected infection then the rash a few days after fever is attributed to drug allergy
what herpes virus causes kaposi sarcoma? what cells is it found in
HHV8 found in B cells and endothelial cells
describe the coxsacki virus
Small, naked, positive strand, ssRNA virus, enterovrius related to poliovirus
what are the 2 skin manifestations of coxsakie virus? explain both
- Herpangina- Throat infection causes red-ringed blisters and ulcers on the tonsils and soft palate “painful red blisters in the mouth”
- Hemorrhagic conjunctivitis-Begins as eye pain, then red, watery eyes with swelling, light sensitivity and blurred virus
what is the common name for the coxsacki virus? why is it called this?
hand foot and mouth disease
-painful red blisters in the throat, tongue, gums, hard palate, inside the cheeks and palms of hands and soles
how is coxsacki spread?
- Spread on hands and surfaces, contaminated feces and salvia
- also aerosol spread from sneezes and coughs
describe the HPV virus
Small naked DNA virus
T/F: there will be inflammation associated with the HPV rash
NO. warts are NOT red because there is no inflammation
describe the poxvirus in molluscum contagiosum
large enveloped DNA virus
describe the rash in molluscum contagiosum
Lesions are pearly, flesh colored, raised and umbilicated (due to a small collapse in the vesicle)
what is the virus in small pox?
variola virus
what children should not get the small pox vaccine?
kids with eczema! and kids that are immunosuppresed (necrosum or gangrenosum)-the immunosuppresed kids will die
describe the measles virus
Paramyxovirus, enveloped, negative strand RNA
describe the spots seen in measles. are they contagious?
Koplik’s spots: small red spots with bluish centers on the buccal mucosa
this rash is NOT contagious!! the virus is spread by respiratory spread during times of aymptomatcy
describe the virus in rubella
Togavirus, enveloped, positive strand RNA
what will the presenting signs of rubella be?
Will see maculopapular rash, lymphadenopathy, arthralagia
is the rubella rash contagious?
NO! it is spread via respiratory droplets
