DERM - Infectious causes of skin disease I Flashcards
definition: exanthem
rash that appears abruptly and involves several areas of the skin at once (Greek: a breaking out)
definition: enanthem
an eruption upon a mucous membrane
what is the exanthem of measles / rubeola? what is the enanthem?
- exanthem: erythematous macules and papules which begin on the face and spread cephalo-caudad and centrifugally
- enanthem: koplik’s spots
- exanthem: erythematous macules and papules which begin on the face and spread cephalo-caudad and centrifugally
- enanthem: koplik’s spots
measles / rubeola
how is measles / rubeola transmitted?
aerosolized respiratory droplets
confluent, morbiliform rash and kopliks spot - diagnosis?
measles / rubeola
what is the exanthem of rubella (German measles)? what is the enanthem?
- exanthem: pruritic, pink to red macules and papules, begin on face and spread to neck, trunk, and extremities over 24 hours - facial rash clears on day 2, rash clears without pigmentary change or scaling by day 3
- enanthem: 20% have petechial lesions on soft palate and uvula (Forchheimer’s sign)
- exanthem: pruritic, pink to red macules and papules, begin on face and spread to neck, trunk, and extremities over 24 hours - facial rash clears on day 2, rash clears without pigmentary change or scaling by day 3
- enanthem: 20% have petechial lesions on soft palate and uvula (Forchheimer’s sign)
rubella (German measles)
what is the exanthem of erythema infectiosum?
- exanthem: starts with bright red cheeks, as the facial rash fades over 1-4 days a symmetric, erythematous reticular (lace-like) eruption appears on trunk and extremitites, lasts 5-9 days
what is the organism responsible for erythema infectiosum?
parvovirus B19
what is the exanthem of exanthem subitum?
pink macules and papules surrounded by white halos; begins on neck and spreads to proximal extremities
what is the most common exanthem before age 2?
exanthem subitum
what is the prodrome of exanthem subitum?
- high fever
- palpebral edema
- cervical lyphadenopathy
- mild upper respiratory symptoms
- as fever subsides, rash appears**
- high fever
- palpebral edema
- cervical lyphadenopathy
- mild upper respiratory symptoms
- as fever subsides, rash appears**
exanthem subitum
pink macules and papules surrounded by white halos; begins on neck and spreads to proximal extremities
exanthem subitum
what is the exanthem of hand foot mouth disease? what is the enanthem?
- exanthem: progression of lesions - bright pink macules and papules to painful vesicles with erythematous halos to erosions with surrounding erythema
- enanthem: erythematous erosions resembling aphthae (canker sores)
what is the exanthem of varicella?
progresses from macules to papules, to vesicles over 12-14 hours, tends to start on face then move to trunk
progresses from macules to papules, to vesicles over 12-14 hours, tends to start on face then move to trunk
varicella
what is the genome of molluscum contagiosum?
double stranded DNA pox virus
what is erythrasma? what areas does it affect? what is the appearance?
- chronic bacterial infetion caused by corynebacterium minutissimum
- affects toes, groin, axilla
- sharply demarcated border, red or brown, may be pruritic or burning
punched out ulcers surrounded by raised margins, covered with yellow crust
ecthyma
what is the organism responsible for regular folliculitis? hot tub folliculitis?
- regular: pseudomonas
- hot tub: pseudomonas
what is hidradenitis suppurativa? what is the most common etiologic agent?
- chronic suppurative infection of apocrine sweat glands
- staph aureus
what is the etiologic agent of erysipelas?
group A strep
- perioral pallor
- strawberry tongue
- pastia’s lines
diagnosis? causative agent?
- scarlet fever
- group A strep
what is the characterizing finding of necrotizing fasciitis?
anesthesia of the skin of affected area
