Spiny keratoderma of the palms and soles.

Six cases of a dermatosis characterized by "music box spine" keratotic papules limited to the palms and soles have been reported. The names that have been used for this type of dermatosis most commonly incorporate the term porokeratosis; for example, "porokeratosis palmaris et plantaris," or "punctuate porokeratotic keratoderma." We suggest the name "spiny keratoderma of the palms and soles," because the clinical, histologic, and electron microscopic features of this entity are distinct from porokeratosis. In addition, unlike porokeratosis, this entity has not shown malignant potential. We report a case of "spiny keratoderma of the palms and soles" and show that topical 5-fluorouracil is an effective treatment.