The food labeling system for food allergens was introduced from April 2002 in Japan. To confirm the effectiveness of the system, we regularly conduct a nationwide food allergy survey every 3 years.
The survey was conducted in cooperation with over 1000 volunteer allergists in Japan at 2001, 2002, 2005 and 2008. We sent questionnaire to contributing doctors every 3 months based on the past survey system, and contributing doctors were asked to report immediate type food allergy cases seen by those doctors. In this survey, immediate type food allergy was defined as the patients who had developed symptoms due to food allergic reaction within 60 minutes after intake of offending food. The details of questionnaire consisted of age, sex, cause of food allergy, symptoms, CAP system, and type of onset.
A total of 8581 immediate type food allergy cases were reported by the doctors. The most common offending foods were hen's egg (39.0%), milk products (18.0%), wheat (9.4%), fruit (5.3%), crustacean (4.6%), peanuts (3.7%), fish egg, buckwheat and fish (3.6%). The most common clinical symptom was observed on skin (89.7%) followed by respiratory system (29.6%). Interestingly, the causes of food allergy were completely different from infancy (egg, milk, and wheat) to adulthood (wheat, crustacean and fruits). Anaphylactic shock was observed in 10.9% of the total reported cases. The cases of anaphylactic shock were due to hen's egg (27.1%), milk products (21.4%) and wheat (18.1%). Eleven percentages of patients had been hospitalized.
We revealed the current condition of the immediate type food allergy cases seen in Japan recent decade. Based on these data, countermeasures against food allergy are ongoing in collaboration with the Ministry of Health, Labour, and Welfare in Japan in order to improve quality of life of patients.