Food Allergies

Overview

Food allergy is an immune system reaction that occurs soon after eating a certain food. Even a tiny amount of the allergy-causing food can trigger signs and symptoms such as digestive problems, hives or swollen airways. In some people, a food allergy can cause severe symptoms or even a life-threatening reaction known as anaphylaxis.

Food allergy affects an estimated 8% of children under age 5 and up to 4% of adults. While there's no cure, some children outgrow their food allergies as they get older.

It's easy to confuse a food allergy with a much more common reaction known as food intolerance. While bothersome, food intolerance is a less serious condition that does not involve the immune system.

Symptoms

For some people, an allergic reaction to a particular food may be uncomfortable but not severe. For other people, an allergic food reaction can be frightening and even life-threatening. Food allergy symptoms usually develop within a few minutes to 2 hours after eating the offending food. Rarely, symptoms may be delayed for several hours.

The most common food allergy signs and symptoms include:

1.Tingling or itching in the mouth

2.Hives, itching or eczema

3.Swelling of the lips, face, tongue and throat or other parts of the body

4.Wheezing, nasal congestion or trouble breathing

5.Abdominal pain, diarrhea, nausea or vomiting

6.Dizziness, lightheadedness or fainting

Anaphylaxis

In some people, a food allergy can trigger a severe allergic reaction called anaphylaxis. This can cause life-threatening signs and symptoms, including:

1.Constriction and tightening of the airways

2.A swollen throat or the sensation of a lump in your throat that makes it difficult to breathe

3.Shock with a severe drop in blood pressure

4.Rapid pulse

5.Dizziness, lightheadedness or loss of consciousness

Emergency treatment is critical for anaphylaxis. Untreated, anaphylaxis can cause a coma or even death.

Risk factors

Food allergy risk factors include:

1.Family history. You're at increased risk of food allergies if asthma, eczema, hives or allergies such as hay fever are common in your family.

2.Other allergies. If you're already allergic to one food, you may be at increased risk of becoming allergic to another. Similarly, if you have other types of allergic reactions, such as hay fever or eczema, your risk of having a food allergy is greater.

3.Age. Food allergies are more common in children, especially toddlers and infants. As children grow older, their digestive systems mature and their bodies are less likely to absorb food or food components that trigger allergies.

Fortunately, children typically outgrow allergies to milk, soy, wheat and eggs. Severe allergies and allergies to nuts and shellfish are more likely to be lifelong.

4.Asthma. Asthma and food allergy commonly occur together. When they do, both food allergy and asthma symptoms are more likely to be severe.

Factors that may increase your risk of developing an anaphylactic reaction include:

1.Having a history of asthma

2.Being a teenager or younger

3.Delaying use of epinephrine to treat your food allergy symptoms

4.Not having hives or other skin symptoms

Complications

Complications of food allergy can include:

1.Anaphylaxis. This is a life-threatening allergic reaction.

2.Atopic dermatitis (eczema). Food allergy may cause a skin reaction, such as eczema.

Prevention

Early exposure

Early introduction of peanut products has been associated with a lower risk of peanut allergy. In a recent study, high-risk infants — such as those with atopic dermatitis or egg allergy or both — were selected to either ingest or avoid peanut products from 4 to 6 months of age until 5 years of age.

Researchers found that high-risk children who regularly consumed peanut protein, such as peanut butter or peanut-flavored snacks, were around 80% less likely to develop a peanut allergy.

Before introducing allergenic foods, talk with your child's doctor about the best time to offer them.

Causes

When you have a food allergy, your immune system mistakenly identifies a specific food or a substance in food as something harmful. In response, your immune system triggers cells to release an antibody known as immunoglobulin E (IgE) to neutralize the allergy-causing food or food substance (the allergen).

The next time you eat even the smallest amount of that food, IgE antibodies sense it and signal your immune system to release a chemical called histamine, as well as other chemicals, into your bloodstream. These chemicals cause allergy symptoms.

The majority of food allergies are triggered by certain proteins in:

1.Crustacean shellfish, such as shrimp, lobster and crab

2.Peanuts

3.Tree nuts, such as walnuts and pecans

4.Fish

5.Chicken eggs

6.Cow's milk

7.Wheat

8.Soy

Treatment

The primary way to manage a food allergy is to avoid consuming the food that causes you problems. Carefully check ingredient labels of food products, and learn whether what you need to avoid is known by other names.

Food Allergies in Children

No parent wants to see their child suffer. Since fatal and near-fatal food allergy reactions can occur at school or other places outside the home, parents of a child with food allergies need to make sure that their child’s school has a written emergency action plan. The plan should provide instructions on preventing, recognizing and managing food allergies and should be available in the school and during activities such as sporting events and field trips. If your child has been prescribed an auto-injector, be sure that you and those responsible for supervising your child understand how to use it.

What are 3 possible signs of a food allergy?

a raised, itchy red rash (hives) – in some cases, the skin can turn red and itchy, but without a raised rash. swelling of the face, mouth (angioedema), throat or other areas of the body. difficulty swallowing. wheezing or shortness of breath.

How long do food allergies last?

How long does it take for a reaction to start after eating a food? Symptoms usually start as soon as a few minutes after eating a food and as long as two hours after. In some cases, after the first symptoms go away, a second wave of symptoms comes back one to four hours later (or sometimes even longer).

Do food allergies go away?

Many people with food allergies wonder whether their condition is permanent. There is no definitive answer. Allergies to milk, eggs, wheat and soy may disappear over time, while allergies to peanuts, tree nuts, fish and shellfish tend to be lifelong.