What underlies this persistent facial rash?

Case 1: For the past month, a 39-year-old woman has had a persistent asymptomatic rash on her face.
She is otherwise healthy and takes no medications.

What is your clinical impression?

A. Rosacea.
B. Sarcoidosis.
C. Cutaneous lupus erythematosus.
D. Polymorphous light eruption.
E. Acne.

Case 1: Rosacea

Rosacea, A, is unusual in an African American but still possible. The precipitating factor appeared to be the stress of recently losing her father. She was treated with oral doxycycline and topical metronidazole.

Skin lesions of sarcoidosis are more inflamed and more papular than this patient’s rash. Cutaneous lupus erythematosus is either inflammatory or features pigmentary changes depending on the type of lupus. Polymorphous light eruption usually manifests with erythematous patches and papules that are often pruritic. The onset of acne would be unusual at age 39 without other precipitating factors.