Nickel sensitivity in the general population.

The incidence of nickel sensitivity in a population above the age of 10 was examined through epicutaneous tests with 5% nickel sulphate performed on certain school and occupational test subjects and on subjects at a home for elderly people. Nickel sensitivity was observed in 4.5% (in 44 cases of 980 tested subjects), in 8% of the females and in 0.8% of the males. In 42 of the 44 nickel-sensitive subjects there was a history of dermatitis from metal contact. At the time of testing, 16 (34%) of the nickel-sensitive subjects revealed eczema. A manifest nickel sensitivity was thus found in 1.6% of all tested subjects, in 2.8% of females and in 0.4% of males. Nickel sensitivity and a simultaneous hand eczema was noted in 0.9% of the tested population, in 1.6% of females and in 0.2% of males. Hand eczemas were rarer (20.5%) in the nickel-sensitive subjects in the population study than in the nickel-sensitive patients tested at the same time in the clinic (56.6%). No case of nickel sensitivity was occupationally related.