Abstract: Objective To report a group of cases characterized by pigmented symmetrical acrokeratoderma. Methods Sixteen patients characterized by pigmented symmetrical acrokeratoderma were collected from outpatients from May 1998 to September 2007 in the Department of Dermatology, Second Affiliated Hospital, Sun Yat-Sen University. General information on the sex, age, profession, family history of patients were documented. All patients underwent clinical and histopathological examinations, and were followed up for the assessment of treatment efficiency. Results Among these patients, 14 were males and 2 were females, ranging in age from 9 to 54 years, with duration of disease varying from 2 months to 8 years （mean course 2.0 ± 1.5 years）. Characteristic manifestations were rough, scaling, brownish auburn or black maculopapular eruptions with mild pruritus. The lesions were symmetrically distributed on palms, dorsal digits and wrists of 16 （100%） patients, elbows and knees of 2 （12.5%） patients, and ankles of 3 （18.8%） patients. Histopathologic examination revealed epidermal hyperkeratosis, acanthosis and papillomatous hyperplasia as well as dermal infiltration with a few lymphocytes. No heredity tendency was observed in any of the patients. The patients showed a poor response to, or experienced a relapse after treatment with oral tretinoins, nicotinamide, vitamin B6 as well as topical tretinoin ointment, glucocorticoid ointment, and so on. Conclusion These cases may represent a new entity clinically characterized by pigmented symmetrical acrokeratoderma, and pathologically characterized by epidermal hyperkeratosis, acanthosis and papillomatous hyperplasia with unknown etiology.

Key words: Aquagenic, Acro, Palmoplantar, Keratoderma