[Result of patch test and allergic contact dermatitis--statistics over the past six years].

Over the past six years we have practised the examination of standard allergen patch test for patients with allergic contact dermatitis or other contact skin diseases and report the data in this paper. Three hundred and ninety-four patients, who complained of itching and skin legion due to contact with chemical agents were examined. Following the widespread use of the patch test procedure, we used eighteen standard allergenic agents and about eighty percent of these patients showed positive reaction. Furthermore, over fifty percent of the patients manifested positive reaction to the plural allergenic agents. The highest percentage of positive reaction was found in the 30-40 years old patients. Of the series of allergenic agents, urushiol caused the highest positive reaction. Among other agents, metal group, e.g., cobalt chloride, and formalin were also high. Many positive patients to paraphenylendiamine (PPI) were engaged in the occupations associated with PPD. This evidence indicates that the materials that are frequently treated at the place of work or homelife play a major role in the pathogenesis of allergic contact skin diseases.