How to identify allergens on food labels?

Food allergies can put your life at risk due to an anaphylaxis reaction. Food allergy affects around 8 % of children worldwide and approximately 3 % of adults. It is crucial to know how to avoid all food allergens, because most of them are used in packaged products (1).

In this brief guide, we will answer the query “How to identify allergens in food labels?” Additionally, we will present information regarding food allergies and what the most common allergens are.

How to identify allergens in food labels?

You can identify food allergens at the back of the package. Normally, food labels have an allergen claim after the ingredient list. The allergen claim could be in the following formats (2):

  • An explicit list of allergens; for example: this product contains milk-derivatives.
  • A guide of how to identify the allergens from the ingredients list; for example: “for food allergens, see ingredients in bold”.

What are Food Allergens?

A food allergen is a substance, known as antigen, inherent to food that causes an allergic reaction in susceptible people. When antigens react with a susceptible immune system, it activates inflammatory reactions in your body (1).

Food allergy is most common in children, but it is present in adults too. Food allergy can cause uncomfortable gastrointestinal symptoms like diarrhea and inflammation, cutaneous eruption, or even severe reactions like anaphylaxis (1). 

Anaphylaxis is a systemic reaction (it involves almost all your organism) when your immune system detects an allergen, it has a rapid progression and could cause death. The symptoms of anaphylaxis are (3):

  • Itchy hands, scalp, and skin.
  • Tachycardia.
  • Dizziness.
  • Difficulty breathing.
  • Cardio circulatory collapse.

Most times, food allergic reactions and anaphylaxis require medical intervention by the administration of antihistamines or steroids (1).

What are the most common food allergens?

The most common food allergens are (1):

  • Milk
  • Egg
  • Wheat
  • Peanuts
  • Nuts
  • Sesame
  • Fish

Food allergies are diagnosed by medical experts using skin or serological tests (1). A food which rarely produces allergic reactions is chicken (4). 

If you want to know more about how to incorporate chicken in your diet, please visit our article on chicken and broccoli as part of a healthy diet.

What is the Importance of Identifying Allergens in Food Labels?

It is extremely important to identify allergens in food labels because food allergic reactions can be aggressive and severe. You can put your life at risk with a food allergy, especially if you get an anaphylaxis reaction, and you are far from a medical center (1).

Moreover, food allergy is most common in kids, so it is critical to look at the ingredients of packaged foods if your child has a food allergy (1).

What Should You Do if You Have an Allergic Reaction?

The first thing to do if you know you have an allergy is avoiding the allergen; however, if you are already experiencing a food allergy reaction, you should go immediately to a healthcare facility or with a physician (5).

Sometimes it is recommended that, under medical prescription, carry on with you an epinephrine auto injector. Epinephrine is an alpha and beta adrenergic agonist drug with rapid (almost instantly) (5). 

Epinephrine increases the heart contractions and reduces vessels’ and mucosa inflammation, therefore, it is ideal to revert the effects of anaphylaxis. If you have an epinephrine auto injector, use it immediately if you suspect you have an anaphylaxis reaction (5).

However, take into account that epinephrine is just to control the anaphylaxis, you must go to a healthcare facility or with a physician for monitoring further symptoms and reactions (5).  


In this brief guide, we answered the query “How to identify allergens in food labels?” Additionally, we presented information regarding food allergies and what the most common allergens are.


  1. Valenta R, Hochwallner H, Linhart B, Pahr S. Food allergies: the basics. Gastroenterology, 2015;148(6):1120-31.e4.
  1. Temple NJ, Fraser J. Food labels: a critical assessment. Nutrition, 2014;30(3):257–60.
  1. Baseggio Conrado A, Ierodiakonou D, Gowland MH, Boyle RJ, Turner PJ. Food anaphylaxis in the United Kingdom: analysis of national data, 1998-2018. BMJ, 2021;372:n251.
  1. Hemmer W, Klug C, Swoboda I. Update on the bird-egg syndrome and genuine poultry meat allergy. Allergo J Int, 2016;25(3):68–75.
  1. Brown JC, Simons E, Rudders SA. Epinephrine in the management of anaphylaxis. J Allergy Clin Immunol Pract, 2020;8(4):1186–95.

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