D2.256 - Aquagenic syringeal acrokeratoderma: a diagnostic challenge triggered by water exposure

Background: Aquagenic syringeal acrokeratoderma (ASA) is a rare, acquired dermatosis characterized by the rapid development of translucent white papules, palmar skin thickening and hyperwrinkling following brief exposure to water. It may be associated with medications and diseases such as cystic fibrosis, atopy, malnutrition, viral infection or be idiopathic. Due to its rarity and overlapping with other aquagenic dermatoses, particularly aquagenic urticaria, ASA is frequently underrecognized.

Case Report: We report the case of a 25-year-old female with a personal history of allergic asthma, allergic rhinitis, oral allergy syndrome to Cucurbitaceae and mild eczema. For ten years, she experienced recurrent episodes of intense palmar pruritus, skin thickening and whitish papules triggered by water exposure, with spontaneous resolution within 30–40 minutes. Symptoms were strictly confined to the palms and were not associated with detergents, soaps, seasonal factors, water temperature or saline concentration. No significant personal or family history of cystic fibrosis. Physical examination was unremarkable between episodes. Given the clinical suspicion of an aquagenic dermatosis, diagnostic provocation testing was performed. A standardized water provocation test was negative on the forearm but positive on the palm, inducing pruritus within 5 minutes and the appearance of confluent whitish (not erythematosus) papules with raised borders after 24 minutes of exposure. These findings were consistent with ASA.

Conclusion: Although both ASA and aquagenic urticaria are rare conditions, they differ significantly in clinical features and anatomical distribution. Careful history-taking and site-specific provocation testing are essential for accurate diagnosis. ASA should be considered in patients presenting with transient palmar changes following water exposure to avoid misdiagnosis and inappropriate management, but also due to its recognised association with cystic fibrosis gene mutations, which may warrant further genetic evaluation.