Contact leukoderma associated with the use of hair colors.

Four cases of contact leukoderma associated with the application of hair rinses and permanent and semipermanent hair colors are described. To our knowledge, this association has not been previously reported. Although none had evidence of pigment loss in other sites, Koebner-induced vitiligo cannot be excluded. In our cases hair color ingredients seem to have had a selective toxic effect on melanocytes. Further study of pigment loss from hair colors is warranted, especially in animal and in vitro assays. Patch testing with putative depigmenting agents in patients should be done with caution, so as to minimize potential for depigmentation in cosmetically important anatomic sites.