Other common irritants include detergents, cutting oils, solvents, and cement. Allergic contact dermatitis develops within 24 to 48 hours after exposure to an allergen to which the patient has previously been sensitized. Rhus dermatitis, caused by poison oak, poison ivy, or poison sumac, is the prototypical allergic response. The dermatitis lasts for 10 to 20 days because the rhus oil becomes embedded in the skin. A clue to the diagnosis is its linear pattern.
Topical neomycin is the most common cause of iatrogenic allergic contact dermatitis.
Occasionally, it may be confused with atopic dermatitis limited to the antecubital or popliteal fossae or with nummular dermatitis scattered on the body. Reprinted with permission. Inc. All Rights Reserved.