Prevalence and relevance of allergic reactions in patients patch tested in North America--1984 to 1985.

Between Jan. 1, 1984, and May 1, 1985, 1199 patients with suspected allergic contact dermatitis were patch tested with 32 "standard" allergens, 707 patients with 19 "vehicle and preservative" allergens, and 613 patients with 10 "special study" allergens. Ten dermatologists representing nine geographic centers collected and analyzed data with the use of the American Academy of Dermatology's mainframe computer in Evanston, Illinois. The most common sensitizers identified were nickel, p-phenylenediamine, quaternium-15, neomycin, thimerosal, formaldehyde, cinnamic aldehyde, ethylenediamine, potassium dichromate, and thiuram mix. Each positive reaction was assessed for its clinical relevance.