All the positive reactions were found among those with previous oozing or dermatitis of the ear lobes. All had experienced trouble with some earrings. They were asked to wear the earrings for 48 hours. In the 5 with a positive patch test, all had an eczematous reaction from the earrings. Seven of the 8 with a negative nickel patch test had a similar eczematous reaction when exposed to earrings.
Most costume jewelry is made up of a nickel alloy.
The outcome of the use test was surprising. Those with an unexpected positive use test may be nickel sensitive, having a false negative patch test. Another possibility is that the reaction is caused by local sensitivity, or may be due to irritation or infection. All the girls investigated intend to become hairdressers. Hand dermatitis in hairdressers is often related to nickel allergy.