Cosmetics applied on the nail encompass three types: (1) coatings that harden upon evaporation; (2) coatings that polymerize; and (3) stick-on nail dressings (synthetic covers). The adverse reactions induced by the two first types present with both local reactions and distant contact dermatitis. Whereas nail enamel applications result especially in ectopic contact dermatitis, polymerizing coatings and synthetic covers represent the main culprit for sometimes severe, local reactions. Whatever the nature of the nail cosmetics, they may produce some adverse reactions. They include: (1) local reactions to cosmetics applied on the nail; (2) distant reactions resulting from the use of nail cosmetics; (3) systemic side effects of nail cosmetics; and (4) infection risks from nail cosmetics.