A case of Cinderella: erythema dyschromicum perstans (ashy dermatosis or dermatosis cinecienta).

A 33-year-old healthy Latina (from either Mexico or Central America) woman with Fitzpatrick type V skin complained of a 2-year history of progressive hyperpigmentation on the axillary folds, dorsal hands, upper neck spilling onto the jawline area, and lower abdomen. There was no preceding dermatitis. The lesions were asymptomatic. She did not use any prescription or over-the-counter drugs or any herbal supplements. She denied contact with any new substances and did not start any new activities. A full review of systems was negative. Physical examination revealed diffuse symmetric gray patches on the proximal arms radiating from the axillary folds with extension onto the trunk (Figure 1). This discoloration was also present on the dorsal hands (Figure 2), upper neck and jawline, and lower abdomen. The lesions were nonpalpable and without erythema. Thyroid function test results and morning cortisol levels were normal. Two adjacent 4-mm punch biopsies were performed on the right axillary skin, one consisted of unaffected skin and one of hyperpigmented skin. Figure 3 shows affected axillary skin with an interface dermatitis and significant pigment dropout. There was no evidence of depositional process of substances such as heavy metals, drugs, or tattoo. There was no evidence of an actinic process. Differential diagnosis included erythema dyschromicum perstans (EDP), fixed-drug reaction, or interface drug reaction. As the patient was not taking any medications, the overall clinical and histologic impression was most consistent with EDP. The patient was started on a low-potency topical steroid twice a day to the affected areas. In addition, because the patient was concerned about the cosmetic appearance of the hyperpigmentation, a 4% hydroquinone cream was started twice daily to the neck area.