Patch testing in cases of eczema and dermatitis in Beijing, China.

Of 124 patients with eczema and dermatitis patch tested by the European standard series of allergens in the period from April to October 1989, 59 cases showed sensitivity to 1 or more allergens. Potassium dichromate, nickel sulphate and cobalt chloride were the 3 major sensitizers, with a frequency of 17.9%, 13.8% and 10.6%, respectively. The office and factory workers showed a higher incidence of positive reactions than the student group. The environment of the office and the factory seems to be the potential source of exacerbating factors of eczematous skin disease.