ABSTRACT
Contact dermatitis, an infl ammatory skin disease characterized by itching, redness, and skin lesions, is caused by skin contact with either an irritant or an allergenic chemical. Acute irritant contact dermatitis arises on initial contact with an adequate concentration of a direct-acting cytotoxic chemical. Whereas, allergic contact dermatitis (ACD) usually arises following more than one skin contact (induction and elicitation) with an allergenic chemical. The skin response of ACD is delayed, immunologically mediated, and consists of varying degrees of erythema, edema, and vesiculation. In the Gell and Coombs system (1968), it is classified as a cell-mediated, tuberculin-like, Type IV allergy.
