Palmoplantar keratoderma

Palmoplantar keratodermas are a heterogeneous group of skin disorders characterized by abnormal thickening (scleroderma) of the stratum corneum of the palms and soles.

Autosomal recessive, dominant, X-linked, and acquired forms have all been described in medical literature.

Types

Clinically, three distinct patterns of palmoplantar keratoderma may be identified: diffuse, focal, and punctate.

Diffuse

Diffuse palmoplantar keratoderma is a type of palmoplantar keratoderma that is characterized by an even, thick, symmetric hyperkeratosis over the whole of the palm and sole, usually evident at birth or in the first few months of life. Restated, diffuse palmoplantar keratoderma is an autosomal dominant disorder in which hyperkeratosis is confined to the palms and soles. The two major types can have a similar clinical appearance:

Diffuse epidermolytic palmoplantar keratoderma (also known as "Palmoplantar keratoderma cum degeneratione granulosa Vörner", "Vörner's epidermolytic palmoplantar keratoderma", and "Vörner keratoderma") is one of the most common patterns of palmoplantar keratoderma, an autosomal dominant condition that presents within the first few months of life, characterized by a well-demarcated, symmetric thickening of palms and soles, often with a "dirty" snakeskin appearance due to underlying epidermolysis.

Diffuse nonepidermolytic palmoplantar keratoderma (also known as "Diffuse orthohyperkeratotic keratoderma", "Hereditary palmoplantar keratoderma", "Keratosis extremitatum progrediens", "Keratosis palmoplantaris diffusa circumscripta", "Tylosis", "Unna–Thost disease", and "Unna–Thost keratoderma") is inherited as an autosomal dominant condition and is present from infancy, characterized by a well-demarcated, symmetric, often "waxy" keratoderma involving the whole of the palms and soles.

Focal

Focal palmoplantar keratoderma, a type of palmoplantar keratoderma in which large, compact masses of keratin develop at sites of recurrent friction, principally on the feet, although also on the palms and other sites, a pattern of calluses that may be discoid (nummular) or linear.

Focal palmoplantar keratoderma with oral mucosal hyperkeratosis (also known as "Focal epidermolytic palmoplantar keratoderma", "Hereditary painful callosities", "Hereditary painful callosity syndrome", "Keratosis follicularis", "Keratosis palmoplantaris nummularis", and "Nummular epidermolytic palmoplantar keratoderma") is an autosomal dominant keratoderma that represents a clinical overlap syndrome with pachyonychia congenita type I but without the classic nail involvement.

Punctate

Punctate palmoplantar keratoderma is a form of palmoplantar keratoderma in which many tiny "raindrop" keratoses involve the palmoplantar surface, skin lesions which may involve the whole of the palmoplantar surface, or may be more restricted in their distribution.