Riehl Melanosis in a 27-Year-Old Bahraini Woman

Hyperpigmentation usually results from either melanocyte hyperplasia or melanocyte hyperactivity. Diffuse hyperpigmentation should prompt a search for offending medications or chemicals or systemic disease. Riehl melanosis is a nonpruritic pigmented dermatosis characterized by brownish-grey facial pigmentation and is almost synonymous with pigmented contact dermatitis of the face, the most common causes of which are sensitizing chemicals in cosmetics. It produces a type IV cytolytic reaction at the epidermal basal layer. Subsequent damage to the basement membrane leads to leakage of melanin, which is ingested by dermal macrophages. Here, we present a case of a 27-year-old woman with patchy, blue-grey-brown pigmentation on her face and neck. The patient had been using perfumes and cosmetics.