Exposure to
hair dye is the most frequent route of sensitisation to
para-phenylenediamine (
PPD), a common contact
allergen. International studies have examined the profile of
PPD, but Australian-sourced information is lacking. Patients are often dissatisfied with advice to stop dyeing their hair. This study examines patients' characteristics, patch test results and outcomes of
PPD allergy from a single Australian centre, through a retrospective analysis of patch test data from 2006 to 2013 at the Liverpool Hospital Dermatology Department. It reviews the science of
hair dye allergy, examines alternative
hair dyes and investigates strategies for hair dyeing. Of 584 patients, 11 were allergic to
PPD. Our
PPD allergy prevalence rate of 2% is at the lower end of international reported rates. About half these patients also react to para-toluenediamine (PTD). Affected patients experience a significant lifestyle disturbance. In all, 78% tried alternative
hair dyes after the patch test diagnosis and more than half continued to
dye their hair. Alternative non-
PPD hair dyes are available but the marketplace can be confusing. Although some patients are able to tolerate alternative
hair dyes, caution is needed as the risk of developing an
allergy to other
hair dye ingredients, especially PTD, is high.