Occupational asthma caused by two herb materials, Dioscorea batatas and Pinellia ternata

There have been very few cases of occupational allergies caused by herb materials. In this paper, we report a case of occupational asthma and rhinitis caused by two herb materials, Dioscorea batatas and Pinellia ternata, which are known as Sanyak and Banha respectively. The patient had strong positive responses to grass pollens and cat fur, as well as to Sanyak and Banha extracts on skin-prick tests. Bronchoprovocation tests showed a dual asthmatic response to Sanyak whereas only an early asthmatic response to Banha. Serum specific IgE and IgG4 antibodies to Sanyak were detected by enzyme-linked immunosorbent assay (ELISA) but there was no specific IgE antibody binding to Banha. In order to further characterize the allergenic component of these extracts, sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and electroblotting studies were also performed. Three IgE binding components (29,000, 57,000, 63,000 Da) were detected within the Sanyak extracts, but no IgE-binding component was noted within the Banha extracts. It is suggested that Sanyak can induce IgE-mediated bronchoconstriction in an exposed worker. Further studies are needed to investigate the pathogenetic mechanism triggered by Banha.