Allergic contact dermatitis elicitation thresholds of potent allergens in humans

Literature scoured for human allergenicity to individual chemicals yields a limited number of potent sensitizers, which can be classified in four cate gories: metals, botanicals, biocides and miscellany. Potency is defined as strong for substances eliciting eczematous reactions to patch concentration s of 500 ppm (parts per million) or less in sensitized individuals. Most da ta encountered stem from studies conducted on dermatology patients tested r outinely for hypersensitivity; only few data have been generated by systema tic serial dilution testing. (C) 2001 Published by Elsevier Science Ltd.