Aquagenic (pseudo) keratoderma (aquagenic palmoplantar keratoderma, aquagenic wrinkling of palms).

Aquagenic palmoplantar keratoderma (APK) is an uncommon hereditary or sporadic condition that is characterized by edematous flat-topped papules appearing on palmar skin with wrinkling after brief water exposure. APK has been associated with cystic fibrosis (CF), presenting with the same mutations found in CF (usually ΔF508 of the CFTR gene), either homozygous or heterozygous. APK may be idiopathic or drug-induced. The diagnosis is easily made if one is aware of this entity. Topical aluminum hydroxide and botulinum toxin injections are the most commonly used treatments. The sporadic form may have a shorter course compared with the hereditary one, resolving spontaneously after a few years. The condition should no longer be considered a true keratoderma but rather a pseudo keratoderma, and in spite of the many different names found in the literature, the term "aquagenic (pseudo) keratoderma" seems to be the most appropriate one.