Erythema dyschromicum perstans.

A 39-year-old Hispanic man presented with widespread, symmetric, hyperpigmented, brown-gray-blue, oval-to-circular, discrete and coalescing patches on the upper extremities, trunk, neck and face, many with an associated annular erythematous border. Histopathologic features showed an interface dermatitis, thin lichenoid and superficial perivascular infiltrates, and dermal melanophages. These changes were consistent with a diagnosis of erythema dyschromicum perstans (EDP). The etiology of EDP is unknown, but many associations have been described. The rim of erythema that appears during the inflammatory phase of the disorder distinguishes it from other disorders of hyperpigmentation. There is no consistently effective treatment for EDP. We highlight the use of narrow-band UV B phototherapy in the treatment of this disorder, which has shown good success in our patient thus far.