[Focal acral hyperkeratosis].

Focal acral hyperkeratosis is a disorder characterized by hyperkeratotic papules along the border of the hands and feet. Focal acral hyperkeratosis and several marginal punctate keratodermas closely resemble acrokeratoelastoidosis of Costa. The question if there is a difference between acrokeratoelastoidosis of Costa and focal acral hyperkeratosis or if they are variants of the same entity are discussed. We report a case showing focal acral hyperkeratosis, review the clinical and histological features of related conditions and present a modified concept of marginal papular acrokeratodermas.