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Role of body piercing in the induction of metal allergies.

BACKGROUND
Metal allergies have been linked to body piercing in women, but few studies have explored this phenomenon in men. It has been postulated that nickel/cobalt and nickel/palladium exhibit coreactivity in patients allergic to metals.


OBJECTIVES
(1) Determine the incidence rate and the source for the induction of metal allergy in 3 groups of men: unpierced, one site-pierced, and multiple sites-pierced; and (2) evaluate the degree of coreactivity between nickel/cobalt and nickel/palladium.


METHODS
Men aged 18 to 43 years (n = 118) were patch-tested using the North American Contact Dermatitis Group's protocol to nickel sulfate 2.5%, gold sodium thiosulfate 0.5%, cobalt chloride 1%, and palladium chloride 1%.


RESULTS
Eleven (9.3%) subjects had at least 1 positive reaction. When characterized by the number of pierced sites, positive reactions were seen in 2 of 50 (4.0%) unpierced, 3 of 27 (11.1%) one site-pierced, and 6 of 41 (14.6%) multiply pierced men. The number of piercings was a statistically significant predictor of metal allergy (P = .04). Four (66.7%) cobalt and no palladium reactions occurred in nickel-positive subjects. The source for the induction of the allergic response was primarily jewelry, which accounted for 5 of 6 nickel allergies and 2 of 3 gold allergies. Silver jewelry was a significant predictor of an allergic response.


CONCLUSION
This study represents the first report that the number of body piercings has positive bearing on the incidence of metal allergy in men. The data also support the theory of coreactivity for nickel/cobalt, but not for nickel/palladium.