. 2022 Jun 29;33(4):293–301. doi: 10.1097/DER.0000000000000915

TABLE 4.

Prevalence of Positive Patch Test Reactions to Selected Hair Dyes (Standard and Hairdressers Series) in Hairdressers

Number Tested	Hair Dye Precursor	Patch Test Positive	Hands as Site of Symptoms	Country	Study Period	Source
136	PPD	63 (46%)	123 (90%) ACD	Greece	2010–2019	Gregoriou et al¹⁰
	PTD	48 (35%)
	Resorcinol	0
264	PPD	62 (23.5%)	255 hand dermatitis/120 ACD	Germany, Austria, Switzerland	2007–2016	Brans et al⁴
264	PTD	67 (25.2%)	255 hand dermatitis/120 ACD	Germany, Austria, Switzerland	2007–2016	Brans et al⁴
263 (post-NACDG reactions as 366 × 71.9% hairdressers)	PPD	146 (39.9% of all occupational related dermatitis)	183 (78.9% of occupational dermatitis in hairdressers was located on the hands)	United States, Canada	2001–2016	Warshaw et al¹²
218	PPD	53 (24.3%)	Occupational dermatitis	Italy	1996–2016	Mauro et al¹³

ACD, allergic contact dermatitis; NACDG, North American Contact Dermatitis Group; PPD, p-phenylenediamine; PTD, toluene-2,5-diamine.