Keratosis palmoplantaris nummularis ("hereditary painful callosities"). Clinical and histopathologic aspects

Three families are described. A number of the members of these families showed nummular keratoses on the plantar pressure points. The lesions usually appeared when the children began to walk. They progressed slowly and were often accompanied by pain. The hands showed only minor lesions, which frequently followed manual labor. Extrapalmoplantar lesions were rare. The histopathologic findings in our patients were those of focal epidermolytic hyperkeratosis. The classification of this type of dominant hereditary focal palmoplantar keratosis, for which the name keratosis palmoplantaris nummularis is suggested, is discussed.