ABSTRACT

Contact dermatitis is an infl ammatory condition caused by direct skin exposure to an offending chemical with or without a requirement for ultraviolet light. There are two distinct types of contact dermatitis: irritant contact dermatitis (ICD) and allergic contact dermatitis (ACD). ACD, an eczematous disease mediated through immune mechanisms, is an acquired skin disorder that occurs at sites of contact with small chemical haptens in only those individuals who have been previously exposed to, and immunologically sensitized to a particular chemical. In contrast to ICD typically only a small percentage of the population develops an eruption when exposed to chemicals causing ACD. The most common chemical allergens causing the condition in North America include nickel sulfate (NiSO4), as well as the pentadecylcatechols, the active moiety in plants of the genus Rhus, which include poison ivy, poison oak, and poison sumac (1).