Para-phenylenediamine allergy: current perspectives on diagnosis and management.

Para-phenylenediamine (PPD) is the commonest and most well-known component of hair dyes. Oxidative hair dyes and dark henna temporary tattoos contain PPD. Individuals may be sensitized to PPD by temporary henna tattooing in addition to dyeing their hair. PPD allergy can cause severe reactions and may result in complications. In recent years, frequency of positive patch test reactions to PPD has been increasing. Cross-sensitization to other contact allergens may occur, in particular to other hair dye components. Hairdressers are at a high risk for PPD allergy and require counseling regarding techniques to minimize exposure and protective measures while handling hair dye. We focus this review on the current perspectives of diagnosis and management of PPD allergy.