Exfoliative dermatitis from Chinese herbs (decoction)--an example of purely epidermal contact-type hypersensitivity to ingested medicines.

A patient, aged 78, with exfoliative dermatitis due to the ingestion of Chinese herbs (decoction) was presented. Provocative medication showed that he was sensitive to 4 composite materials (Radix angelicae acutilobae, Rhizoma zingiberis, Radix paeoniae and Radix glycyrrhizae). Patch tests were positive to each of these materials while the intradermal test was negative. These results indicate that systemic contact-type hypersensitivity to the ingested medicines is involved in evoking the exfoliative dermatitis lesion and that, in addition, purely epidermal contact sensitivity as defined by S. Epstein and Baer plays an important role.