Contact allergy to hair-colouring products: a cosmetovigilance follow-up study by four companies in Europe from 2014 to 2017.

BACKGROUND

A previous analysis of undesirable events (UEvs), reported to four major companies following the use of hair-colouring products in Europe, showed that the reporting rates were stable for both oxidative and direct hair-colouring products over the period 2003-2006.

OBJECTIVES

In order to verify the impact of risk management measures implemented since 2006, as well as the impact of a new Commission Regulation (No 1223/2009), the same four companies analysed cosmetovigilance data collected over an additional four-year period (2014-2017). The objective was to determine whether there was any time effect, country effect, or product type effect, as well as identify risk factors.

MATERIALS AND

METHODS

Each company collected reports of alleged UEvs, undesirable effects (UEfs) and serious undesirable effects (SUEs) for their products in their key European markets, and calculated the respective reporting rates (number of events/million units sold). A detailed analysis was performed on allergic contact dermatitis-type events.

RESULTS

The reporting rates for alleged UEvs and allergic-type UEfs associated with hair-colouring products remained stable over the four-year period, although a statistically significant decrease was observed for some companies. No time effect on SUEs was observed for three companies but a statistically significant decrease in SUEs was observed for one company. Black henna tattoos remained a major risk factor regarding SUEs due to hair dyes.

CONCLUSION

The reporting rates of undesirable events, including contact allergy-type events, were stable over time. This was true for oxidative and direct hair dyes, for both home use and professional exposure scenarios.