Buckwheat anaphylaxis: an unusual allergen in Taiwan.

IgE-mediated hypersensitivity to buckwheat is common in Korea, Japan, and some other Asian countries. However, buckwheat is not a common allergen in Taiwan. We report a woman with asthma who had anaphylactic shock, generalized urticaria, and an acute exacerbation of asthma five minutes after ingesting buckwheat. The patient underwent skin prick and Pharmacia CAP testing (Uppsala, Sweden) for specific IgE to buckwheat, white sesame and soybean as well as other common allergens in Taiwan including Dermatophagoides pteronyssinus (Dp), D. farinae (Df), cat and dog dander, cockroach, egg white, cow milk and codfish. The patient had a strongly positive skin prick test response to buckwheat and positive reactions to Dp and latex. Specific IgE results were class 6 for buckwheat, class 4 for Dp and Df, and class 2 for dog dander, wheat, sesame and soybean. Results of an open food challenge with white sesame and soybean were negative. Although buckwheat is a rare allergen in Taiwan, it can cause extremely serious reactions and should be considered in patients presenting with anaphylaxis after exposure to buckwheat.

Murine Model of Buckwheat Allergy by Intragastric Sensitization with Fresh Buckwheat Flour Extract

Food allergies affect about 4% of the Korean population, and buckwheat allergy is one of the most severe food allergies in Korea. The purpose of the present study was to develop a murine model of IgE-mediated buckwheat hypersensitivity induced by intragastric sensitization. Young female C3H/HeJ mice were sensitized and challenged intragastricly with fresh buckwheat flour (1, 5, 25 mg/dose of proteins) mixed in cholera toxin, followed by intragastric challenge. Anaphylactic reactions, antigen-specific antibodies, splenocytes proliferation assays and cytokine productions were evaluated. Oral buckwheat challenges of sensitized mice provoked anaphylactic reactions such as severe scratch, perioral/periorbital swellings, or decreased activity. Reactions were associated with elevated levels of buckwheatspecific IgE antibodies. Splenocytes from buckwheat allergic mice exhibited significantly greater proliferative responses to buckwheat than non-allergic mice. Buckwheat-stimulated IL-4, IL-5, and INF-gamma productions were associated with elevated levels of buckwheat-specific IgE in sensitized mice. In this model, 1 mg and 5 mg dose of sensitization produced almost the same degree of Th2-directed immune response, however, a 25 mg dose showed blunted antibody responses. In conclusion, we developed IgE-mediated buckwheat allergy by intragastric sensitization and challenge, and this model could provide a good tool for future studies.