DERM - Infectious causes of skin disease I

Question 1

definition: exanthem

Answer 1

rash that appears abruptly and involves several areas of the skin at once (Greek: a breaking out)

Question 2

definition: enanthem

Answer 2

an eruption upon a mucous membrane

Question 3

what is the exanthem of measles / rubeola? what is the enanthem?

Answer 3

• exanthem: erythematous macules and papules which begin on the face and spread cephalo-caudad and centrifugally
• enanthem: koplik’s spots

Question 4

• exanthem: erythematous macules and papules which begin on the face and spread cephalo-caudad and centrifugally
• enanthem: koplik’s spots

Answer 4

measles / rubeola

Question 5

how is measles / rubeola transmitted?

Answer 5

aerosolized respiratory droplets

Question 6

confluent, morbiliform rash and kopliks spot - diagnosis?

Answer 6

measles / rubeola

Question 7

what is the exanthem of rubella (German measles)? what is the enanthem?

Answer 7

• 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)

Question 8

• 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)

Answer 8

rubella (German measles)

Question 9

what is the exanthem of erythema infectiosum?

Answer 9

• 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

Question 10

what is the organism responsible for erythema infectiosum?

Answer 10

parvovirus B19

Question 11

what is the exanthem of exanthem subitum?

Answer 11

pink macules and papules surrounded by white halos; begins on neck and spreads to proximal extremities

Question 12

what is the most common exanthem before age 2?

Answer 12

exanthem subitum

Question 13

what is the prodrome of exanthem subitum?

Answer 13

• high fever
• palpebral edema
• cervical lyphadenopathy
• mild upper respiratory symptoms
• as fever subsides, rash appears**

Question 14

• high fever
• palpebral edema
• cervical lyphadenopathy
• mild upper respiratory symptoms
• as fever subsides, rash appears**

Answer 14

exanthem subitum

Question 15

pink macules and papules surrounded by white halos; begins on neck and spreads to proximal extremities

Answer 15

exanthem subitum

Question 16

what is the exanthem of hand foot mouth disease? what is the enanthem?

Answer 16

• 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)

Question 17

what is the exanthem of varicella?

Answer 17

progresses from macules to papules, to vesicles over 12-14 hours, tends to start on face then move to trunk

Question 18

progresses from macules to papules, to vesicles over 12-14 hours, tends to start on face then move to trunk

Answer 18

varicella

Question 19

what is the genome of molluscum contagiosum?

Answer 19

double stranded DNA pox virus

Question 20

what is erythrasma? what areas does it affect? what is the appearance?

Answer 20

• chronic bacterial infetion caused by corynebacterium minutissimum
• affects toes, groin, axilla
• sharply demarcated border, red or brown, may be pruritic or burning

Question 21

punched out ulcers surrounded by raised margins, covered with yellow crust

Answer 21

ecthyma

Question 22

what is the organism responsible for regular folliculitis? hot tub folliculitis?

Answer 22

• regular: pseudomonas

- hot tub: pseudomonas

Question 23

what is hidradenitis suppurativa? what is the most common etiologic agent?

Answer 23

• chronic suppurative infection of apocrine sweat glands

- staph aureus

Question 24

what is the etiologic agent of erysipelas?

Answer 24

group A strep

Question 25

- perioral pallor - strawberry tongue - pastia's lines diagnosis? causative agent?

Answer 25

- scarlet fever | - group A strep

Question 26

what is the characterizing finding of necrotizing fasciitis?

Answer 26

anesthesia of the skin of affected area