The fairly well-defined erythematous plaques covered with silvery scale are typical for psoriasis. In some patients, the disorder may be limited to the genital skin.
A 27-year-old man noted a gradually increasing, asymptomatic rash on the glans penis. The remainder of the cutaneous exam was normal. The family history was strongly positive for psoriasis.
Key point: The “rash” consists of fairly well-defined erythematous plaques, covered with silvery scale. This is typical for psoriasis. This disorder may rarely be limited solely to genital skin.
Treatment: Low-potency topical corticosteroids and/or vitamin D derivatives (such as calcipotriene ointment) will usually resolve genital psoriasis.
Note: The most important differential diagnostic possibilities include seborrhea and balanitis circinata associated with Reiter disease.