Patch Testing With Hair Cosmetic Series in Europe: A Critical Review and Recommendation

The review examined the prevalence and management of contact allergies from hair cosmetics in Europe, highlighting that many ingredients, such as dyes and bleaches, were strong allergens causing allergic contact dermatitis. Data from 19 countries showed a need for a standardized European hair cosmetics series for patch testing, including common allergens like p-phenylenediamine and toluene-2,5-diamine, while excluding outdated substances. The study emphasized the importance of patch testing, particularly for hairdressers, to prevent occupational dermatitis and address medico-legal issues. It recommended a two-part series for routine and specialized testing, stressing the need for regular updates based on clinical and exposure data.