Aquagenic acrokeratoderma

Background  Aquagenic acrokeratoderma (AA) is a rare condition with female predilection that occurs after brief water exposure and disappears minutes to an hour after drying. The pathogenesis remains unclear. Methods  Four Chinese patients with AA were reported and analyzed. Results  There were 2 males and 2 females (age range: 14‐33 years) who presented with a 2‐week to more than 10‐year history of small white papules coalescing into edematous plaques on the hands; lesions appeared within 5‐10 minutes of water exposure, began to regress in 3–20 minutes and disappeared within 5 minutes to one hour after drying. Warm water provoked the lesions more rapidly than cold water. Lesions of a female patient could be triggered by detergent. In another female patient, lesions also involved the feet and were associated with palmoplantar erythema and hyperhidrosis. Biopsy from the lesion of one patient after water exposure revealed hyperkeratosis, mild hypergranulosis, and dilatated eccrine ducts. Biopsy from the lesion of another patient after drying showed normal epidermis and dermis. Two patients were treated with topical formalin 3% in alcohol, and two with 3% potassium aluminium sulfate solution with partial relief without any adverse effects. Conclusion  AA may occur in both males and females and may involve the feet. Warm water triggers the lesions more rapidly than cold. Topical formalin 3% in alcohol and 3% potassium aluminium sulfate solution may be optional therapy.