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:

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.

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.

Ungrouped

Genetics

Epidermolytic palmoplantar keratoderma has been associated with keratin 9 and keratin 16. Nonepidermolytic palmoplantar keratoderma has been associated with keratin 1 and keratin 16.