Spiky keratotic projections on the palms and fingers. Spiny keratoderma

Spiny keratoderma is an infrequent dermatosis consisting of multiple projections located on the palms and soles, with the distinct histopathology feature of a parakeratotic column above a hypogranular epidermis. This entity has been reported under several different names, such as punctate porokeratotic keratoderma, punctate keratoderma, palmar filiform hyperkeratosis, and spiny keratoderma of the palms and soles. Most of the cases described are acquired, although there are also familial cases. Since this disease has been under-diagnosed and under-reported, it is important for dermatologists to keep spiny keratoderma of the palms and soles in mind. We present a familial case of spiny keratoderma and review the literature.