Food protein-induced enterocolitis syndrome due to buckwheat: A case report.

Buckwheat is a rare causative food for food protein-induced enterocolitis syndrome (FPIES). To date, it is unknown what laboratory data patients with FPIES caused by buckwheat show. We report a 4-year-old female with FPIES caused by buckwheat and the laboratory results. Skin prick, specific IgE antibody, and basophil activation tests were negative; however, the lymphocyte stimulation test (LST) revealed a 10.2-fold increase in activation compared with the negative control. In an open-label oral food challenge (OFC) of 80 g boiled buckwheat noodles, 3 hours after ingestion, vomiting occurred four times in a 2-hour duration. Therefore, we diagnosed the patient with FPIES caused by buckwheat. Her neutrophil count, C-reactive protein, and thymus and activation-regulated chemokine were elevated after the OFC. Moreover, the patient had a positive reaction to the LST, which may theoretically be useful in diagnosing non-immunoglobulin E-mediated gastrointestinal food allergies. FPIES caused by buckwheat is rare; however, we found that the same laboratory results were observed in a comparison of FPIES cases caused by other foods.