Dermatology/ Rashes and Exanthems

Question 1

What is an exanthem?

Answer 1

The cutaneous manifestation of a systemic infectious disease

Question 2

What are the six classic infectious agents that cause exanthems?

Answer 2

1. Measles
2. Rubella
3. Roseola
4. Varicella
5. Scarlet fever
6. Erythema infectiosum

Question 3

Infectious agent of Erythema infectiosum (ie, fifth disease)

Answer 3

Parvovirus B19

Question 4

Infectious agent of Roseola

Answer 4

Human herpesvirus 6 (HHV6)

Question 5

Infectious agent of Scarlet fever

Answer 5

S. pyogenes

Question 6

What is the first sign of measles?

Answer 6

Koplik spots—white papules on red base on the buccal surfaces

Question 7

Describe the rash of measles.

Answer 7

Erythematous maculopapular rash that progresses cephalocaudally and then regresses cephalocaudally

Question 8

What are the complications of measles?

Answer 8

• pneumonia
• encephalitis
• subacute sclerosing panencephalitis

Question 9

Describe the rash of rubella.

Answer 9

Fleeting, discrete macules

Question 10

When is rubella infection particularly dangerous? l

Answer 10

Infection in pregnant women causes embryopathy in the fetus.

Question 11

Describe the natural course of roseola.

Answer 11

High fever for 3 days followed by a rash that appears when the fever drops

Question 12

What is the progression of the rash in roseola?

Answer 12

Starts on the trunk and spreads to the extremities

Question 13

What is the treatment of roseola?

Answer 13

Supportive care

Question 14

What is the classic rash of fifth disease?

Answer 14

“Slapped cheeks” and lacy rash (trunk → arms/legs)

Question 15

What is the classic rash of varicella?

Answer 15

Crops of vesicles (dew drops on a red base) beginning on trunk

Question 16

A patient presents with symmetric, violaceous macules on her eyelids. What is this rash and what condition should you suspect?

Answer 16

Heliotrope rash of dermatomyositis