Unilateral erythromelanosis follicularis faciei et colli.

Clinical features and histopathologic findings are described in this case of erythromelanosis follicularis faciei et colli in a 30-year-old man of Chinese descent. This is the fourteenth case in the world literature and the first which is unilateral. Electron microscopic examination revealed abnormalities consisting of a homogeneous mass of pigment in the center of the melanosome and a stippled appearance to the periphery of the organelle. In addition, many of the melanosomes appeared to be abnormally large.