Lenticular acral keratosis in washerwomen.

BACKGROUND: In 1952, a Brazilian dermatologist, Oswaldo Costa, described a dermatosis characterized by accentuation of the cutaneous folds on the knuckles of both hands and small horny papules on the thenar eminences, posterior surface of the wrists, and the interdigital space between thumb and index finger; he called this entity acrokeratoelastoidosis. Other similar entities, such as focal acral hyperkeratosis and marginal keratoelastoidosis, have been described. The features of the different types of lenticular acral keratosis are discussed. MATERIALS AND METHODS: Fifteen patients with lenticular acral keratosis and five controls were studied clinically and pathologically. The skin biopsies were processed for light and transmission electron microscopy. The clinical data were reviewed, and the following variables were recorded: age, sex, distribution and morphology of the lesions, history of exposure to sunlight and objective evidence of photodamage, familial incidence, occupation and hobbies, time of evolution, and response to previous treatments. The results were compared with samples taken at autopsy from five women without dermatoses. RESULTS: All patients were women, with flat, keratotic papules located on the transition between the dorsal and volar surfaces of the fingers and hands. Histologically, there was an increased amount of elastic fibers, which were coarse and tortuous, and appeared to be interrupted in some areas. In contrast, there were sparse, thin fibers in the mid and deep dermis in the skin of controls. Transmission electron microscopy of these papules showed enlarged, thickened elastic fibers, with deposits of electron-dense, coarse clumps. CONCLUSIONS: Our cases do not seem to correspond to any of the three entities which are manifested clinically by acral keratotic plaques. All of these women washed clothes by hand on a stone washboard for many hours every day. As there is no clinical or histologic evidence of actinic damage, chronic trauma seems to be the cause of the dermatosis in this type of patient. We propose the term "occupational lenticular acral keratosis" for our cases.