Food Protein-induced Enterocolitis Syndrome Due to Rice in a Japanese Infant: A Case Report.

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated gastrointestinal food allergy characterized by repetitive vomiting within 1-4 h and/or diarrhea within 24 h after ingesting the causative food. We herein report a rare Japanese case of rice-induced FPIES. A six-month-old, female, Japanese patient presented to the emergency room (ER) with the complaint of vomiting after feeding. Postprandial vomiting had occurred occasionally since she started ingesting solid food at the age of 5 months. Rice-induced FPIES was suspected only after the fourth ER visit based on the characteristic history of recurrent vomiting occurring 1-2 h after ingesting food containing rice. Allergen-specific IgE testing and a skin prick test with an allergen scratch extract were both negative for rice. During an oral food challenge test (OFC), vomiting was observed after the patient ingested 2 g of rice porridge. Based on the OFC results and the entire clinical course, FPIES due to rice was diagnosed. A lymphocyte stimulation test with rice revealed a significantly elevated stimulation index. Rice-induced FPIES is rarely reported among Japanese infants despite rice being a staple in the Japanese diet. The prevalence of rice-induced FPIES differs greatly among populations, suggesting a multifactorial cause associated with its development. Delays in diagnosis are common in FPIES, and our case demonstrates the importance of obtaining a dietary history of food ingested prior to symptom onset in cases of infantile repetitive vomiting.

Pollen-food allergy syndrome and component sensitization in adolescents: A Japanese population-based study.

Allergic rhino-conjunctivitis with pollen allergy has been prevalent worldwide and Pollen-food allergy syndrome (PFAS) refers to individuals with pollen allergy who develop oral allergy syndrome (OAS) on consuming fruits and vegetables. The prevalence of PFAS varies by region and that in Japanese adolescents remains to be elucidated. In this cross-sectional study, we examined the epidemiological characteristics of PFAS in a general population of Japanese adolescents according to pollen allergy, OAS, and IgE component sensitization. Participants comprised adolescents, at age 13 years, from a prospective birth cohort study in Japan. We administered questionnaires to collect information from parents regarding pollen allergy, PFAS and OAS at each child's age 13 years. ImmunoCAP ISAC was used to assess IgE component sensitization. Among 506 participants with a complete questionnaire and ISAC measurement results, 56.5% had a history of hay fever, 16.0% had a history of OAS, 51.0% had pollen allergy, and 11.7% had a history of PFAS; additionally, 72.7% were sensitized to one or more tree, grass, and/or weed allergens. The most common sensitization (95.7%) among adolescents with pollen allergy was to Japanese cedar (Cry j 1). The most common causal foods were kiwi and pineapple (both 39.0%). Knowledge levels about PFAS were poor among affected adolescents. We found a high prevalence of PFAS among adolescents in Japan. Although it affects approximately 1/10 adolescents in the general population, public awareness regarding PFAS is poor. Interventional strategies are needed to increase knowledge and to prevent PFAS in the general population.