― Current Status from Japan's Nationwide Data ―

📊 According to Japan's nationwide monitoring survey on immediate-type food allergies (FY 2024, 6,033 cases analyzed), detailed reports are provided on the frequency of causal foods as well as cases that resulted in anaphylaxis (shock symptoms).
The latest nationwide data in Japan shows that nuts, especially walnuts, are surging as a major cause of immediate-type food allergies and anaphylaxis.
Buckwheat and fish roe, though infrequent, can cause severe reactions even in small amounts, making careful handling based on the nature of the food itself, as well as age, important when introducing them.

🔍 First,top causative foods in immediate-type food allergies overallis as follows.
Eggs: 26.71 TP3T (1,609 cases)
Walnuts: 15.21 TP3T (916 cases)
Milk: 13.41 TP3T (807 cases)
Wheat: 8.11 TP3T (489 cases)
Peanuts: 7.01 TP3T (421 cases)
Ikura: 5.71 TP3T (344 cases)
Cashews: 4.61 TP3T
Shrimp: 3.01 TP3T
⚠️ Of particular note isthe fact that tree nuts, centering on walnuts, have risen to second place as a causative food for allergiesbetween 27 and 36 weeks of pregnancy.
Looking at the annual trends, tree nuts have increased about 14-fold over the 18-year period from 2005 to 2023, with the increase in recent years being extremely remarkable.
📌 From these results, it can be seen that in Japan, in addition to the historically common "eggs, milk, and wheat,"Nuts (especially walnuts) are becoming a major cause of immediate-type allergies and even severe reactions.It is clearly shown that.
🚑 Furthermore, in this survey, out of 6,033 cases of immediate-type food allergy,586 cases (9.71 TP3T) presented with shock symptoms (anaphylaxis).。
When broken down by age, it can be seen that even infants as young as 0 years old have experienced shock symptoms following administration of 8.0%, indicating that severe reactions occur with a certain frequency starting in early childhood.
Furthermore, the prevalence of shock symptoms increases with age, reaching 14.81 TP3T among those aged 18 and older.

📈The proportion of foods that caused immediate-type symptoms and resulted in shock is as follows:between 27 and 36 weeks of pregnancy.
Macadamia nuts: 18.81 TP3T
Wheat: 15.71 TP3T
Pistachios: 14.0%
Cashews: 13.31 TP3T
Milk: 11.81 TP3T
Walnut: 9.41 TP3T
Shrimp: 8.71 TP3T
Eggs: 8.51 TP3T
Peanuts: 8.11 TP3T
Ikura: 6.71 TP3T

Like this,Nuts are not only a food with a high frequency of causing reactions, but also have a high rate of leading to anaphylaxis.is clearly shown by national data from Japan.
🌍 International review papers also identify tree nuts (such as walnuts) and peanuts as representative examples of severe cases and persistent food allergies that are difficult to outgrow naturally, and Japanese data are consistent with these international findings.

Literature
Consumer Affairs Agency, FY2024 Research and Study Project Report on Food Labeling Related to Food Allergies (Immediate-type Food Allergy National Monitoring Survey, n=6,033)
Sicherer SH, Sampson HA. Food allergy: A review. New England Journal of Medicine, 2018
Savage J et al. The natural history of food allergy. Journal of Allergy and Clinical Immunology, 2016

🌾② Buckwheat and Buckwheat Allergy
- Frequency, ranking, and "why it tends to become serious" -
📊 In Japan's nationwide monitoring surveys, buckwheat is not included in the top 5 causative foods.
However,Foods for which a certain number of immediate-type reactions are reported every year and which are clinically prone to be experienced as severe cases (anaphylaxis)is positioned as
Despite being consumed less frequently than nuts and eggs, the reason buckwheat is perceived as "likely to cause severe symptoms" isProperties of Allergen ProteinsIt is located in.
🔬 In English original research, some of the major allergens in buckwheat
Hard to be broken down by digestive enzymes (pepsin)
It has been shown that they easily reach the small intestine while maintaining their antigenicity within the gastrointestinal tract.
For this reason,Even a small intake is strongly recognized by the immune system, easily leading to strong immediate reactions or anaphylaxis.It is considered.

🕰️ Regarding when to start consumption, the guidelines do not provide a clear age criterion for "at what age children can eat buckwheat."
On the other hand, in Japanese clinical settings and explanations for parents,
from around 1.5 to 2 years of age or later, on a day when the child is in good health, starting with a small amount, and at a time of day when it is easy to visit a medical institution,It is often introduced more cautiously than other foods.The reality is that
This is,Safety considerations based on the characteristic that even a small amount can cause severe illnessis due to

Literature
Consumer Affairs Agency, FY2024 Immediate-Type Food Allergy Nationwide Monitoring Survey
Tanaka K et al. Pepsin-resistant 16-kDa buckwheat protein is associated with immediate hypersensitivity. International Archives of Allergy and Immunology, 2002
Yanagida N et al. Reactions during buckwheat oral food challenge are rare but often anaphylactic. International Archives of Allergy and Immunology, 2016

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🐟③ Raw fish / fish roe (salmon roe, cod roe)
- Japanese frequency data and concepts regarding the timing of intake -
📊 According to the nationwide monitoring survey, salmon roe ranks sixth among food-related causes (5.71 TP3T, 344 cases).
Salmon roe accounts for the vast majority of fish roe, while tarako (pollock roe) and kazunoko (herring roe) are limited to a small number of cases.
By age group,Most cases develop from early childhood to school ageIt has been shown that.

While it has been suggested that opportunities to consume fish roe are increasing due to the popularity of conveyor-belt sushi and other factors,
At present, there is no research showing a causal relationship that "the younger age of ingestion is the cause of the increase in allergies."。
This point is also handled with caution in birth cohort studies as well as domestic and international reviews.
Regarding the age at which to start consuming raw fish and fish roe,from the perspective of food safety, apart from allergiesThere is.
International recommendations in the field of food safety (such as those by ANSES) state that children under the age of 3 should avoid raw or undercooked fish, and the reason isRisk of food poisoning caused by bacteria and parasitesbetween 27 and 36 weeks of pregnancy.
📌 For this reason, in Japan, sashimi-style salmon roe and tarako (cod roe)As a general rule, starting around age 3 or older, in small amounts.is often explained.
🌍 Even in international review papers, while fish and fish roe allergies are not as persistent or severe as nut allergies,Caution is required during introduction as there is a potential to cause immediate reactions or anaphylaxis.before the onset of the influenza season.

Literature
Consumer Affairs Agency, FY2024 Immediate-Type Food Allergy Nationwide Monitoring Survey
Makita E et al. Fish roe allergy in Japanese children. Allergology International, 2018
Bernstein AS et al. Fish, shellfish, and children’s health. Pediatrics, 2019

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