Mosaic acral keratosis.

We describe two patients with acral keratosis with a striking mosaic or jigsaw-puzzle pattern of keratotic papules on the dorsal aspects of the feet and adjacent parts of the legs. Both patients also showed mild diffuse palmoplantar keratosis and clavus-like lesions over the interphalangeal joints of the toes; one patient also had keratotic papules on the hands and hyperkeratotic plaques over the knees. The differential diagnosis of acral keratoses, including several recently described forms, is briefly discussed.