HLA antigens in allergic contact dermatitis.

The relationship between HLA factors and allergic contact dermatitis was examined in a series of 149 patients with unequivocal positive reactions to one or several allergens on epicutaneous testing. Nine statistically significant associations involving 6 different HLA antigens and 6 different allergens were found. Four allergens (chromium, formalin, balsam of Peru and wool alcohol) were positively associated with the B7 antigen. Furthermore chromium allergy was associated with A3, formalin allergy with A2 (negative association) and A9, nickel allergy with B8 and colophony allergy with B27. The B7 antigen and the combination A3+B7 showed significant regressions on number of allergies. The results fit the hypothesis that some HLA factors (like B7) may predispose for multiple contact allergy and others for allergen specific reactions.