Irritant nail dermatitis of chemical depilatory product presenting with koilonychia

Chemical hair removal products are available as creams, gels, powders, aerosols and roll-ons and all of these forms work in the same way by breaking chemical bonds between sulfur atoms in the protein. Currently, the common active ingredients of these products are calcium thioglycolate, potassium thioglycolate, arsenic and sulfur minerals. Sulfur and arsenic containing products are important toxic chemicals which are mainly used for removing hair in developing countries. Irritant contact dermatitis accounts for 80% of all contact dermatitis reactions which are often occupation-related. Toluene sulfonamide, formaldehyde resin, acrylates and ethylcyanoacrylate are the most common irritants. Irritant nail dermatitis with plants has been well defined with Lobelia richardii flower, Compositae family and garlic. Although allergic dermatitis, irritant dermatitis and irritant nail dermatitis have been well demonstrated with chemicals, koilonychia is unusual presentation of irritant dermatitis. Here we describe a case of nail irritant dermatitis due to application of chemical depilatory product for hair removal presented with koilonychias. To our knowledge this is the first case of such presentation with koilonychia in the English literature.