Finding alternative hair dyes for individuals allergic to para-phenylenediamine (PPD) has been difficult. Newer permanent and demipermanent hair dyes that have replaced PPD with para-toluenediamine sulfate (PTDS) are now available.
We examined whether individuals allergic to PPD will tolerate PPD-free hair dyes containing PTDS.
A retrospective analysis of patch-test results since October 2006 was done and yielded 28 patients allergic to PPD who were also tested with a hair dye series. From January 2004 through October 2006, seven additional patients allergic to PPD were tested with PTDS but not the full dye series. Patch-test results were analyzed. The newer PTDS dyes were recommended for all PPD-positive PTDS-negative subjects starting in 2008, and these subjects were contacted to determine whether they tolerated the recommended hair-dye products.
Of 28 PPD-allergic patients seen since October 2006, 16 (57.1%) tested negative to all other substances on the dye series. Eleven tested positive to PTDS; of these, several were also allergic to other substances in the hair dye series. There was only one patient who was allergic to ortho-nitro-PPD and not to PTDS. Of 7 additional PPD-allergic patients seen from 2004 through 2006, 4 (57.1%) tested negative to PTDS. In total, 20 of 35 individuals (57.1%) tested positive to PPD but negative to PTDS. Ten of 13 PPD-positive patients for whom PTDS hair dyes were recommended subsequently used a PTDS hair dye, and all tolerated these products.
Fifty-seven percent of patients allergic to PPD in this study will likely tolerate newer permanent and demipermanent hair dyes based on PTDS. Most individuals not allergic to PTDS will also test negative to other substances in the dye series. All 10 patients who tested positive to PPD and negative to PTDS who subsequently used a PTDS dye free of PPD tolerated these products. Many individuals allergic to PPD will benefit from the newer PTDS-based products.