Can urticarial reactions occur from contact with a substance?

Occasionally, urticarial reactions may occur with certain exposures, instead of the eczematous changes seen with ACD and ICD (Fig. 9-1). Allergic contact urticaria involves a specific IgE–mast cell interaction, resulting in the release of vasoactive compounds. While urticaria occurs at the site of contact, more generalized symptoms can appear, including angioedema, anaphylaxis, rhinoconjunctivitis, and widespread urticaria. A good example is the latex glove immediate reaction reported in health care professionals. Nonimmunologic contact urticaria occurs secondary to a non–antibodymediated release of vasoactive mediators or due to a direct effect on the cutaneous vasculature. Many agents found in cosmetic products can cause a nonimmunologic contact urticaria. These include sorbic acid, benzoic acid, and cinnamic acid. This may explain the facial burning and stinging that some patients experience using cosmetics. To diagnose contact urticaria, a prick test is usually performed. In this test, a small amount of the allergen is placed on the skin, and a needle is used to prick the skin. An urticarial wheal of appropriate size constitutes a positive test, usually developing within 15 to 20 minutes after allergen administration (Fig. 9-2).

Rietschel RL, Fowler JF: Contact urticaria. In Rietschel RL, Fowler JF, editors: Fisher’s contact dermatitis, Hamilton, Ontario, 2008, BC Decker, pp 615–634.