In a study of Japenese dermatology patients, a high incidence of gold sensitization was found in those with pierced ears. Of the 377 patients patch tested with 18 different metal salts, 37 (34.6%) of the 107 with pierced ears reacted to 0.2% aqueous gold chloride, significantly higher than the two reactions seen in the 270 with intact ear lobes. The frequencies of reactions to mercuric chloride and nickel sulfate were also increased in the subjects with pierced ears.