What is a food allergy?

Food allergy is an abnormal reaction of the body's immune system to certain food ingredients, usually triggered by proteins, which can lead to itchy skin, difficulty breathing, and even shock.This article will start fromDefinition and mechanism, common allergenic foods, symptoms and diagnosis, prevention and managementIt is developed at four levels to help readers systematically understand this health problem.

1. Definition and immune mechanism of food allergy

The essence of food allergy is that the immune system misjudges harmless food proteins as "enemy" and triggers an immediate reaction mediated by IgE antibodies or a delayed reaction mediated by non-IgE.For example, the Ara h1 protein in peanuts may trigger a vigorous immune response.According to statistics from the World Allergy Organization, about 5%-8% of children and 2%-5% of adults worldwide suffer from food allergies. Among them, milk and egg allergies are common in infants and young children, while allergies to nuts and seafood often persist into adulthood.

2. High-risk foods and cross-reactions

The following are common allergenic foods and related ingredients:

food category	Major allergens	High-risk groups
milk	Casein, whey protein	infants
eggs	ovomucoid	Children 1-3 years old
peanuts	Ara h1-3 protein	all ages

Pay attention to cross-reactions. For example, people allergic to birch pollen may develop oral allergy syndrome to apples and carrots.

3. Symptom classification and medical diagnosis

Food allergy symptoms range from mild (such as hives) to fatal (such as laryngeal edema).Diagnosis requires a combination ofskin prick test, serum IgE detection and food challenge test.The American Allergy Society points out that 90% of allergies can be initially screened through blood tests, but the final diagnosis needs to be made by a professional doctor.

4. Daily management and emergency response

Strictly avoiding allergenic foods is the core measure. When reading food labels, pay attention to the "may contain" warning.Carry an epinephrine auto-injector (such as EpiPen, manufacturer: Mylan) with you to deal with sudden allergies.Studies have found that introducing peanuts early (such as 4-6 months of age) may reduce the risk of allergy, but it needs to be done under the guidance of a doctor.

Summary and reminder

Food allergies need to be confirmed through scientific diagnosis and should not be made on your own.Parents should pay attention to children's reactions after eating, and adults should seek medical attention promptly if they experience allergic symptoms for the first time.At present, desensitization treatments (such as oral immunotherapy) are still under research, so do not try them blindly.Staying vigilant and taking reasonable precautions are key.

Quote sources:
1. World Allergy Organization (WAO) "Global Allergy White Paper" 2021 Edition
2. American Academy of Allergy, Asthma, and Immunology (AAAAI) Clinical Guidelines
3. Allergy UK cross-reactivity data
4. Epinephrine syringe manufacturer: Mylan (product name: EpiPen)