Disseminated spiked hyperkeratosis

Multiple small hyperkeratoses were observed in a 42-year-old woman. They had first appeared in early adult life. There was a history of an apparently identical disorder affecting her father, her brother, and her brother's son. A similar condition has been described in four previous reports in which seven individual cases have been documented. Four had a positive family history, bringing the total number of previously known cases to 14. The disorder is characterized by the development in early adult life of widely disseminated small spikes of keratin that are unrelated to hair follicles. Microscopic examination shows digitate orthokeratosis with moderate epidermal cell hyperplasia and a normal underlying dermis.