What is the definition of Food Allergy?

A food allergy is type of immune response triggered by eggs, peanuts, milk, shellfish or some other specific food.

What are the alternative names for Food Allergy?

Allergy to food; Food allergy - peanuts; Food allergy - soy; Food allergy - fish; Food allergy - shellfish; Food allergy - eggs; Food allergy - milk

What are the causes for Food Allergy?

Many people have a food intolerance. This term usually refers to heartburn, cramps, belly pain, or diarrhea that can occur after they eat foods such as:

  • Corn products
  • Cow's milk and dairy products (lactose intolerance)
  • Wheat and other grains that contain gluten (celiac disease)

A true food allergy is much less common.

The immune system normally protects the body against harmful substances, such as bacteria and viruses. It also reacts to foreign substances called allergens. These are usually harmless, and in most people, do not cause a problem.

Food allergies

In a person with a food allergy, the immune response is oversensitive. When it recognizes an allergen, the immune system launches a response. Chemicals such as histamines are released. These chemicals cause allergy symptoms.

Any food can cause an allergic reaction. The most common food allergies are to:

  • Eggs (mostly in children)
  • Fish (older children and adults)
  • Milk (people of all ages)
  • Peanuts (people of all ages)
  • Shellfish such as shrimp, crab, and lobster (people of all ages)
  • Soy (mostly in children)
  • Tree nuts (people of all ages)
  • Wheat (people of all ages)

In rare cases, food additives, such as dyes, thickeners, and preservatives can cause a food allergy or intolerance reaction.

Some people have an oral allergy. This is an allergy type syndrome that affects the mouth and tongue after they eat certain fresh fruits and vegetables:

  • Melons, apples, pineapple, and other foods contain substances that are similar to certain pollens.
  • The reaction most often occurs when you eat the raw form of the foods. How severe the reaction is depends on how much of the food you eat.

What are the symptoms for Food Allergy?

Symptoms usually begin within 2 hours after eating. Sometimes, the symptoms begin hours after eating the food.

Key symptoms of a food allergy include hives, a hoarse voice, and wheezing.

Other symptoms that may occur include:

  • Swelling (angioedema), especially of the eyelids, face, lips, and tongue
  • Trouble swallowing or breathing due to swelling in the throat
  • Itching of the mouth, throat, eyes, skin, or any other area
  • Lightheadedness or fainting
  • Nasal congestion, runny nose
  • Stomach cramps, diarrhea, nausea, or vomiting
Perioral dermatitis

Symptoms of mouth (oral) allergy syndrome:

  • Itchy lips, tongue, and throat
  • Swollen lips (sometimes)

In a severe reaction, called anaphylaxis, in addition to the above symptoms, you may have low blood pressure and blocked airways. This can be life threatening.

What are the current treatments for Food Allergy?

If you suspect that you or your child has a food allergy, see an allergy specialist doctor (allergist).

Treatment may involve any of the following:

  • Avoiding the food (this is the most effective treatment).
  • Desensitization, during which you eat a small amount of the food each day. This must be done under an allergist's guidance.

Other treatments, including allergy shots and probiotics, have not been proven to help with food allergies.

If your child has a problem with cow's milk formula, your provider may suggest trying a soy-based formula or something called an elemental formula, if it is available.

If you have symptoms on only one area of the body, for example, a hive on the chin after eating the food, you may not need any treatment. The symptoms will likely go away in a brief time. Antihistamines may relieve the discomfort. Soothing skin creams may also provide some relief.

If you have been diagnosed with a food allergy, learn how to use injectable epinephrine. You should have it with you at all times. If you develop any type of serious or whole-body reaction (even hives) after eating the food:

  • Inject the epinephrine.
  • Then go to the nearest hospital or emergency facility right away, preferably by ambulance.

What are the support groups for Food Allergy?

The following groups can provide more information about food allergies:

  • American Academy of Allergy Asthma and Immunology -- www.aaaai.org/Conditions-Treatments/Allergies/Food-Allergy
  • Food Allergy Research and Education (FARE) -- www.foodallergy.org/
  • National Institute of Allergy and Infectious Diseases -- www.niaid.nih.gov/diseases-conditions/food-allergy

What is the outlook (prognosis) for Food Allergy?

Allergies to peanuts, tree nuts, and shellfish tend to last a lifetime.

Read food labels

Avoiding the problem foods may be easy if the food is uncommon or easy to identify. When eating away from home, ask detailed questions about the food you are served. When buying food, read package ingredients carefully.

What are the possible complications for Food Allergy?


Anaphylaxis is a severe, whole-body allergic reaction that is life threatening. Although people with oral allergy syndrome may have an anaphylactic reaction in rare cases, they should ask their doctor if they need to carry injectable epinephrine.

Food allergies can trigger or worsen asthma, eczema, or other disorders.

When should I contact a medical professional for Food Allergy?

Steps to take when a food allergy reaction occurs:

  • Call your local emergency number, such as 911, if you have any serious or whole-body reactions, particularly wheezing or difficulty breathing, after eating a food.
  • If your provider prescribed epinephrine for severe reactions, inject it as soon as possible, even before calling 911. The sooner you inject the epinephrine, the better.
  • Anyone who has had an allergic reaction to a food should be seen by an allergist.

How do I prevent Food Allergy?

Breastfeeding may help prevent allergies. Otherwise, there is no known way to prevent food allergies.

A common belief and practice is to delay introducing allergy-causing foods to infants until their gastrointestinal tract has had a chance to mature. The timing for this varies from food to food and from baby to baby.

Avoiding peanuts in early childhood does not appear to prevent, and may even enhance, the development of peanut allergy. Doctors now suggest introducing peanut-containing foods to infants, which may prevent peanut allergy. Talk to your child's provider to learn more.

Once an allergy has developed, carefully avoiding the offending food usually prevents further problems.



Bird JA, Jones S, Burks W. Food allergy. In: Rich RR, Fleisher TA, Shearer WT, Schroeder HW, Frew AJ, Weyand CM, eds. Clinical Immunology: Principles and Practice. 5th ed. Philadelphia, PA: Elsevier; 2019:chap 45.

Sicherer SH, Lack G, Jones SM. Food allergy management. In: Burks AW, Holgate ST, O'Hehir RE, et al, eds. Middleton's Allergy: Principles and Practice. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 82.

Togias A, Cooper SF, Acebal ML, et al. Addendum guidelines for the prevention of peanut allergy in the United States: report of the National Institute of Allergy and Infectious Diseases-sponsored expert panel. J Allergy Clin Immunol. 2017;139(1):29-44. PMID: 28065278 pubmed.ncbi.nlm.nih.gov/28065278/.

  • Journal: The Egyptian journal of immunology
  • Published —
Prevalence of confirmed immunoglobulin E-mediated food allergy among adult Egyptian patients.
  • Condition: IgE Mediated Food Allergy in Eastern Mediterranean Children
  • Journal: Allergologia et immunopathologia
  • Treatment Used: Oral Food Challenge (OFC)
  • Number of Patients: 1361
  • Published —
This study evaluated the oral food challenge (OFC) in Eastern Mediterranean children with IgE mediated food allergy.
Clinical Trial
  • Status: Active, not recruiting
  • Phase: N/A
  • Intervention Type: Behavioral
  • Participants: 40
  • Start Date: February 1, 2021
Feasibility of a Group Intervention Using Cognitive Behavioural Therapy (CBT) to Reduce Anxiety for Children Aged 12-17 With Food Allergy.
Clinical Trial
  • Status: Recruiting
  • Phase: Phase 2
  • Intervention Type: Drug
  • Participants: 72
  • Start Date: July 9, 2019
T Cell Reagent Research for Monitoring T Cells in Food Allergy (MOTIF) Phase 2 Study Using Food Allergen Oral Immunotherapy for Shrimp or Cashew Allergies