Shellac.

Shellac is a common ingredient in cosmetics such as mascaras, lipsticks, nail polish, and hairsprays. As an emerging contact allergen in patients with eyelid dermatitis and contact cheilitis, it was added to the 2009-2010 North American Contact Dermatitis Group screening panel. Consideration of this allergen should be given with patients who present with allergic contact dermatitis in areas where shellac-containing substances were applied.