Morbilliform rash

Question 1

How soon after drug initiation does morbilliform drug eruption occur?

Answer 1

7-14 days

Question 2

What are the most common drug related causes of morbilliform eruption?

Answer 2

Beta lactams

Bactrim

Anticonvulsants

Allopurinol

Question 3

Patient with history of sore throat develops morbilliform rash, dx?

Answer 3

EBV infection treated with ampicillin (almost 100% of patients with mono treated with amp get this)

Question 4

Up to 40% of AIDS patients get a morbilliform rash if treated with ______

Answer 4

Bactrim

Question 5

Describe the clinical presentation and course of morbilliform rash.

Answer 5

starts as red-pink macules and papules in groin and axilla

• later, symetrically distributed macules and papules on trunk and upper extremities often with pruritis (this is a good clue for drug culprit as opposed to viral exanthem which are not usually itchy)
• can have low grade fever
• spares mucous membranes

- subsides after 1-2 weeks after drug cessation

Question 6

Management of morbilliform drug eruption:

Answer 6

• supportive, topical CS for itch, stop drug

- can “treat through” if the medication is essential as very low rate of progression to SJS/TEN