Spiny keratoderma: a common under-reported dermatosis.

Spiny keratoderma is a dermatosis consisting of multiple projections located on the palms and soles, with a distinct histology characteristic of a parakeratotic column above a hypogranular epidermis. We report six cases discovered within a year and review the present literature on spiny keratoderma. The average age of the patients was 57 years. Fifty-seven percent of the patients were male and forty-three percent were female. The duration of lesions ranged from 4 months to 40 years. Symptoms were variable, however, lesions were often unnoticed by the patient. The location of the lesions involved the palms and soles or the palms alone. Past medical history was significant for hypertension and hyperlipidemia treated with HMG-CoA reductase inhibitors. Lesions often occurred in patients involved in manual labor. Spiny keratoderma is a relatively common under-reported dermatosis found most often in older patients with history of manual labor and is possibly related to treatment with HMG-CoA reductase inhibitors.