A new article published in Food and Chemical Toxicology reported that allergic and irritant skin reactions caused by topical exposure to permanent hair dyes are a common problem. The article elaborated that permanent hair dyes are formed by a mixture of ingredients that vary from low to extreme skin sensitizing potency that inter-react to form unknown by-products. This article illustrated a trial wherein p-phenylenediamine (PPD), resorcinol (RES), H2O2 were topically exposed to RhE, alone or as a mixture. Subsequently, parameters related to skin irritation such as epidermal viability, keratinocytes damage, barrier loss and interleukin (IL)-1 α were evaluated. The results showed that ingredients tested alone did not lead to an increase of cytotoxic parameters related to skin irritation. On the contrary, when the mixture of PPD/H2O2/RES and PPD/H2O2 was applied to the RhE, some of the parameters such as morphological changes, including the presence of apoptotic cells, barrier loss and increased IL- 1 α release were noted. The results indicated that the mixture of ingredients used in permanent hair dyes have an irritant effect in RhE, whereas the ingredients alone do not.¹

Reference

1. Zanoni T, Pedrosa T, Catarino C et al. Allergens of permanent hair dyes induces epidermal damage, skin barrier loss and IL-1 α increase in epidermal in vitro model. Food and Chemical Toxicology. 2017. doi:10.1016/j.fct.2017.12.033.