The color of skin: Brown diseases of the skin, nails, and mucosa

AbstractBrown diseases comprise disorders leading to hyperpigmentation in skin and nail. Melasma is an acquired skin disorder that is characterized by brownish macules that typically occurs on the face. Schamberg’s disease, also known as progressive pigmented purpura, is characterized by brown pigmentation with pepper spots on their edges. We summarize the epidemiology, pathogenesis, histologic features, and treatment choices for additional brown diseases, including melasma, pigmented purpuric dermatoses, postinflammatory hyperpigmentation, drug-induced hyperpigmentation, and pigmentations due to systemic and/or physiologic conditions.