Abstract
Patch testing（PT）is useful for identifying the causes of dermatitis that is resistant to palliative treatment. However, PT of substances that are encountered in daily life sometimes produces false-negative results, which can cause dermatologists to overlook possible causes of dermatitis, even if they have conducted careful interviews with patients prior to PT. The Japanese standard allergens（JSA）are useful for identifying allergens among substances that produce false-negative results during PT and for drawing attention to unexpected causes of allergic reactions that might not be suspected before PT. When performing PT, the JSA should be used as much as possible. Since 2015, 22 standard allergens have been readily available in Japan. It is expected that more Japanese dermatologists will employ PT in daily clinical practice.
