Case 3: How do you explain this persistent facial rash?

A 17-year-old boy presents with an intermittent asymptomatic rash on his cheeks that he says started 1 year earlier after a trip to Arizona over spring break. He is otherwise healthy, takes no medications, and has no other rashes.

Which of the following would you include in the differential?

A. Rosacea.
B. Atopic dermatitis.
C. Keratosis pilaris.
D. Polymorphous light eruption.
E. Cutaneous lupus erythematosus.

(answer on next page)

Case 3: Cutaneous lupus erythematosus

When the rash did not respond to treatment for eczema, B, or rosacea, A, a biopsy was performed; the results revealed the diagnosis of cutaneous lupus, E. An oral antimalarial (hydroxychloroquine) and topical dapsone were prescribed. The patient was also told to limit sun exposure and to use sunscreen with a high SPF. The results of the patient’s subsequent blood work were all normal.

The biopsy results ruled out polymorphous light eruption, and the appearance of this patient’s rash was too inflammatory to be keratosis pilaris.