D2.125 - Occupational asthma in hairdressers due to hair dyes containing para-amino compounds

Persulphate salts in hair bleaches are a well-documented cause of occupational asthma (OA) among hairdressers, but little information is available on OA caused by hair products containing other chemicals. 

The aim of this study was to investigate the asthmagenic potential of hair dyes containing p-phenylenediamine (PPD) and/or other para-amino compounds (PACs). 

This retrospective multicentre study was conducted among 99 hairdressers with OA ascertained by a positive specific inhalation challenge (SIC) with hair products between 2006 and 2018. Ten hairdressers (10%) had a positive SIC response to oxidative hair dyes containing PPD and/or PACs.

Eight hairdressers developed a bronchial response during “work-simulation” SICs with hair dyes, whereas two subjects were challenged with pure PPD. The pattern of bronchial reaction was isolated late, dual, and isolated early in 4, 3, and 2 subjects, respectively. One subject developed an isolated increase in sputum eosinophils consistent with eosinophilic bronchitis. A significant post-challenge increase in non-specific airway hyperresponsiveness was detected in three of the seven subjects (43%) with both pre- and post-SIC measurements available. Among subjects with fractional exhaled nitric oxide (FeNO) measurements (n=3) or sputum eosinophil counts (n=4) available both pre- and post-SIC, none showed a significant increase in FeNO post-SIC, and only one subject demonstrated an increase in sputum eosinophils post-SIC. 

Hair dyes containing PACs may substantially contribute to OA among hairdressers. This possibility should be considered carefully when evaluating hairdressers with symptoms of work-related asthma.