Background:Urea containing topical products are extensively marked for treatment of nail diseases. Side effects are rare and mainly include irritation of the periungual skin, when topicals with high urea concentration are applied too widely on the digit, or covered by tape.Main observation:We report a case of a 84-year-old man with an erosive-bullous eruption of the 1st and the 2nd left toes due to application of an urea-containing cream, that he had regularly applied every night covering the digit with a plastic bandage. Suspecting an allergic contact dermatitis, we performed patch test with the Italian Standard series called SIDAPA and the product (Xérial 50 Extrême cream®) itself. Patch test readings showed a positive reaction to colophony contained in the plastic band and to the cream.Conclusion:Our case is the first report of allergic contact dermatitis to a cream containing a high concentration urea utilized for treatment of nail thickening under occlusion.