Paraphenylenediamine (PPD) is a black dye with well known sensitizing properties. Its increasing use as a skin paint to produce temporary 'tattoos' has led to recent reports of allergic contact dermatitis. Hitherto, such cases of allergic contact dermatitis due to PPD have been localized to the original site of application of the skin paint. We report two cases of severe allergic reactions to paint-on 'tattoos'. Both of these patients had no prior history of sensitivity to PPD, although case 2 had previously used permanent hair dyes. In both cases, the primary eruption at the 'tattoo' site was followed within days by a generalized eruption which ultimately required treatment with oral corticosteroids, because the initially prescribed topical corticosteroids proved ineffective.