Spiny keratoderma: case report, classification, and treatment of music box spine dermatoses.

The classification of palmoplantar lesions resembling music box spines is confusing, and nearly all attempts at treatment have been futile. We present the case of a 62-year-old white man with symptomatic music box spine lesions on his palms and fingers composed of parakeratotic columns over a hypogranular epidermis. Lesions and symptoms disappeared after a short course of 6 percent salicylic acid gel applied under occlusion. We suggest a classification scheme for this and similar-appearing conditions under the title spiny keratoderma, based on their histologic pattern (parakeratotic or hyperkeratotic) and anatomical location (palmoplantar, diffuse, or associated with epidermal appendages).