[Porokeratosis plantaris, palmaris et disseminata].

A 74-year-old patient has been affected for about 40 years by hardly discomforting keratotic lesions of the trunk and extremities, especially on the palms and soles. Some of his children and grandchildren have shown similar lesions. Histologically the diagnosis of porokeratosis was established by demonstration of a cornoid lamella. Clinically it appeared to be the rare form of porokeratosis plantaris, palmaris et disseminata, in which mainly the palms and soles are affected by hyperkeratotic papules, but nearly the whole body may be involved. It is discussed how this genodermatosis can be differentiated from other forms of porokeratosis. The family tree of our patient is compatible with autosomal dominant inheritance.