These are the most common allergens in hair dyes

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 (Image: Pixabay CC0)
(Image: Pixabay CC0)
Hair dyes can easily trigger contact allergies. In a large-scale project, the Information Network of Dermatological Clinics (IVDK) has investigated which substances are most frequently involved. The importance of hair dyes for allergies is thus evident. Safety at the workplace and product safety should be improved, the scientists involved now wrote in their study.

Wolfgang Uter, epidemiologist at the University of Erlangen-Nuremberg, and co-authors of the study, among them Kränke Birger from the Department of Dermatology and Venerology at Med Uni Graz, now wrote in the scientific journal "Contact Dermititis": "Hair cosmetic products contain several, sometimes strong contact allergens including preservatives. Hairdressers* often have hand dermatitis, consumers* (customers as well as self-users* at home) can also develop severe dermatitis of the scalp or face."

Long study period

To find out the most common causes of this, the experts* analyzed the results of skin patch tests and clinical information from people professionally in contact with hair dyes and from consumers* in the period between the beginning of 2013 and the end of 2020. The information was collected as part of the Information Network of Skin Clinics (IVDK), based in Göttingen, Germany. There were data from 920 hairdressers with a mean age of 28 years, 84 percent of whom had inflammation of the hands, and from 2,321 consumers (mean age: 49 years), nearly 72 percent of whom had developed contact dermatitis on the head or face.

The contact eczema was apparently most frequently triggered by P-phenylenediamine (PPD; in 19.7 percent of the affected hairdressers and in 31.6 percent of the customers) and by toluene-2,5-diamine (20 percent among affected professional users, 30.8 percent among customers). On the other hand, the professional users were more frequently allergic to substances such as ammonium persulfate and glyceryl thioglycolate than the customers. All of these substances have an oxidative effect and are used for permanent hair coloring.

PPD, for example, has long been at the top of the list of contact allergy triggers. Sensitization rates of 40 to 50 percent have been reported from the hairdressing profession. The substance is contained in around one hundred hair dye products - this was the result of a study carried out as part of a diploma thesis at the University Clinic for Dermatology and Venerology in Graz in 2020.

Safety in the workplace to be improved

Contact allergies are common overall. From all possible causes, about five percent of men and eleven percent of women are likely to experience such an episode within a year. If possible, however, the cause should naturally be avoided. When in doubt, this also applies to the substances from oxidative hair dyes. "Hair dyes were the most common sensitizing substances among both hairdressers and consumers*. The importance of allergies due to hair dyes is evident and often characterized by cross-allergies. Workplace safety and product safety should be further improved," the scientists wrote.

The Information Network of Dermatological Clinics (IVDK) with dozens of clinic departments specialized in allergies from Germany, Austria and Switzerland as members wants to act as a monitoring system for potential triggers of such health problems. The anonymized data of patients are evaluated in order to draw conclusions about the spread and possible prevention of contact allergies triggered by environmental influences.

Text reference: from 07.08.2023