Rôle of ear piercing in metal allergic contact dermatitis.

To evaluate the effect of ear piercing on sensitization to gold and other metals, diagnostic patch testing with 18 metals was performed. 377 patients (65 men and 312 women, ranging in age from 15 to 78 years; mean 34.2, S.D +/- 15.1 years) were patch tested; 107 had pierced earlobes. Metals were applied on the back for 2 days, and the results read with the ICDRG scoring system 3 days after application. Reactions of + to +3 were regarded as positive. There were significantly more patients reacting to gold chloride (p < 0.001), mercuric chloride and nickel sulfate (p < 0.05) in patients with pierced ears than in those without. Statistical issues included: (i) a significant number of patients with pierced ears referred because of earring dermatitis; (ii) those with pierced ears represented a different age group from those without; (iii) a significant number of patients without eczema in the non-pierced ear group. However, our data suggests that ear piercing is a risk factor not only for nickel but also for gold sensitization. Gold was the second most frequent metal allergen after nickel in the pierced group.