Chinese bellflower root anaphylaxis: IgE-binding components and cross-reactivity with mugwort and birch

A 56-year-old man who had suffered from seasonal rhinitis in spring and autumn experienced recurrent generalized urticaria and an oral burning sensation after eating several cooked herbs for 3 months. A skin-prick test showed positive responses to various pollens, celery, Chinese bellflower, and arrowroot. The Chinese bellflower-specific IgE ELISA OD value was 1.547. Oral challenge with unprocessed raw Chinese bellflower root provoked oral burning sensation, eyelid swelling, generalized urticaria, and hypotension. In an ELISA inhibition test, IgE binding to Chinese bellflower was significantly inhibited by Chinese bellflower, mugwort, and birch pollen extract. SDS-PAGE and immunoblot assay revealed nine IgE-binding components, and common protein bands were detected in the range of 40~55 kDa (Chinese bellflower-mugwort-birch) and 14 kDa (Chinese bellflower-birch). Chinese bellflower root can cause anaphylaxis and may have cross-reactivity with mugwort and birch.