Amulet string contact leukoderma and its differentiation from vitiligo.

A young adult factory worker presented with a linear depigmented vitiliginous patch on his right arm at the site where a silver amulet had been fixed with a nylon thread. He claimed that it was occupational in origin and demanded compensation, but patch testing with the nylon thread of the amulet and its extracted dyes proved that the contact leukoderma was due to the thread.