Biphasic buckwheat anaphylaxis:Case report and systematic review.

Buckwheat anaphylaxis is commonly recognized in Europe and Asia, and there is only one case reported in Taiwan so far. Here, we report a case of biphasic buckwheat anaphylaxis in a 57 year-old male patient who lost consciousness twice in the same day after having buckwheat noodles. The serum test shows that Dermatophagoides pteronyssinus (Dp)immunoglobulin E (IgE) (42.4 kU/L) and buckwheat-specific IgE (81.5 kU/L) are unusually high. Although biphasic buckwheat anaphylaxis is rare, we should still be aware the second episode could be life-threatening and happen within a day after the exposure to the buckwheat antigen.