Prevalence of dichromate sensitivity.

In a population of 822 healthy adult volunteers, 2% of the 410 men and 1.5% of the 412 women showed a positive patch test reaction to 0.5% potassium dichromate in pet. Most of the positive reactions (10/14) occurred in the group of 110 offset printers, lithographers and printing plant cleaners with present occupational exposure to chromium. Among the remaining test population, sensitivity to dichromate was rare (4/712). Of the 14 chromium-allergic persons, 9 had present or past hand eczema, 2 had eczema only on the face, and 3 could not recall having had any skin trouble. In 2981 clinic patients tested during a 5-year period, the frequency of chromate sensitivity was 6.8% in men and 2.8% in women among all patients tested, but 20% in men and 8% in women of the 499 patients with occupational hand eczema. The incidence of chromium allergy in separate occupational groups is presented.