Individual and Sociodemographic Factors Associated with Polysensitization at a New York City Hospital.

Allergic contact dermatitis (ACD) is a cutaneous delayed-type hypersensitivity response with a global prevalence estimated at over 20%.1 The gold standard for diagnosis is patch testing, in which allergens are applied to a patient's skin to elicit cutaneous responses in sensitized individuals. Many patients undergoing patch testing test positive for 3 or more unrelated allergens, termed polysensitization.2 A recent North American Contact Dermatitis Group study found that 32.1% of patients tested were positive to at least three allergens, but reported rates vary.3