Keratosis extremitatum (Greither's disease): clinical features, histology, ultrastructure.

Keratosis palmoplantaris progrediens et transgrediens (Greither's disease) was first described by Greither in 1952. The inheritance pattern is autosomal dominant with variable expression. The clinical manifestation is characterized by diffuse palmoplantar keratoderma associated with hyperhidrosis and progressive extension of keratoderma to the dorsum of the hands and feet. In addition, hyperkeratotic plaques may occur on the elbows and knees. We describe a 44-year-old patient with typical features of Greither's disease. Immunohistologic and ultrastructural investigations are presented.