(medicine) The condition of having keratin growing on the skin.

(medicine, pathology, dermatology) A potentially precancerous skin lesion, typically on the upper portion of the head, characterized by discolored, thickened or scaly growths of keratin and caused by repeated exposure to ultraviolet light, such as from sunlight or tanning beds.

A genetic follicular condition causing rough reddish bumps on the skin.

(medicine, otorhinolaryngology) An ear disease where a dense plug of keratin is present in the deep meatus of the ear.