Description

Palmoplantar keratoderma (PPK) constitutes a heterogeneous group of disorders characterized by thickening of the palms and the soles. The various forms of PPK can be divided into hereditary forms with only skin problems (isolated PPK), hereditary syndromes with PPK and associated features such as lesions of skin, hair, teeth, nails, or sweat glands and/or with abnormalities of other organs, and acquired forms. Inherited PPKs can be divided into three classes based on clinical patterns of epidermal involvement: 1) in diffuse PPK there is a uniform involvement of the palmoplantar surface, which usually present within the first few months of life; 2) in focal and striate PPK there is localized areas of hyperkeratosis located mainly on pressure points and sites of recurrent friction; 3) punctate keratoderma presents with multiple small, hyperkeratotic papules, spicules, or nodules on the palms and soles. These tiny keratoses may involve the entire palmoplantar surface or may be restricted to certain locations. Depending on the gene involved, inheritance of PPK can be autosomal dominant or autosomal recessive.