Are these comedones acne--or something else?

For several months, a 59-year-old man, who works as a gardener, has noticed dark spots along the hairline of the lateral forehead. The lesions are asymptomatic.

What are you looking at here?

A. Acne
B. Chloracne.
C. Rosacea.
D. Actinic comedones.
E. Colloid milia.

(Answer on next page.)
 

Answer: Actinic Comedones

Chronic sun exposure produces actinic skin changes—referred to as dermatoheliosis—such as the actinic comedones, D, seen here. These lesions usually respond to the use of sunscreen daily and tretinoin cream nightly.

The patient’s age and the eruption sites—only sun-exposed areas—ruled out acne. The patient had no history of exposure to chemicals that precipitate chloracne. Rosacea does not feature comedones. Colloid milia typically present on the back of the hands.