Approximately 32 million Americans live with at least one food allergy. This includes 10.8% of adults and 7.6% of children.
The most common food allergies in adults are (in order of prevalence):
- cow's milk
- tree nuts
- fin fish
- tree nuts
- cow's milk
- fin fish
People can have non-allergic reactions to foods, known as food intolerances. These often get mistaken as a food allergy.
Food allergy research is ongoing. As research evolves, a better understanding of food allergy diagnosis and management emerges.
What are food allergies?
A person with a food allergy has an immune system that overreacts to certain proteins found in particular foods. The immune system sees the food protein as a dangerous intruder. It creates a specific antibody called IgE (Immunoglobulin E). This antibody fights off the intruder. It also triggers the allergic response. The response can involve skin, respiratory, heart and/or digestive symptoms. These can range from mild to a severe systemic reaction. Systemic reactions are known as anaphylaxis.
A food allergy is different from food intolerance. Food intolerances are when people eat a food and it gives them an upset stomach or cramping. People with food allergies may experience stomach symptoms and other body symptoms.
Visit a board-certified allergist if you think you may have food allergies. They can take a history of your symptoms and conduct testing if needed.
Myth: I have a gluten allergy.
Fact: Gluten is not a food allergen; it is a protein composite found in wheat, barley, and rye. Some people experience stomach problems from eating gluten. This is a gluten intolerance, not an allergy. An intolerance is a digestive issue while an allergy is an immune system response.
Celiac disease is a disease in which people must avoid gluten, but it not due to an allergy. Rather, people with celiac disease must avoid gluten because it causes a serious autoimmune response. A gluten-free diet eliminates many nutritious foods that are high in fiber, vitamin B, zinc, and iron. Talk with your doctor before eliminating gluten from your diet.
People may have an allergy to wheat, but that is not the same thing as celiac disease or gluten allergy. A wheat allergy is an immune system response triggered by exposure to wheat protein. Wheat allergy symptoms may overlap with gluten intolerance or celiac disease. People with wheat allergies may also experience an allergic reaction involving other body systems. If you think you may have a wheat allergy, visit a board-certified allergist for testing.
Myth: I can treat anaphylaxis with antihistamines.
Fact: Antihistamines can help relieve non-life-threatening allergic reactions, such as mild hives. When symptoms intensify, it’s a life-threatening severe reaction called anaphylaxis. Symptoms may include:
- shortness of breath;
- tightness or swelling in the throat;
- severe hives;
- heart problems;
- digestive problems.
Anaphylaxis must be treated immediately with epinephrine. Epinephrine is the first line of treatment for anaphylaxis. It acts quickly to relieve symptoms. If you are experiencing anaphylaxis, use epinephrine first and use epinephrine fast. Delayed use of epinephrine is often the cause of poor outcomes or even fatalities.
Allergic emergencies can last for hours. Seek immediate medical attention for any severe allergic reaction. Carry two epinephrine auto-injectors with you at all times. It’s common to experience a second allergic reaction up to 12 hours later or longer. Symptoms are often milder than the initial reaction. However, you may need a second dose of epinephrine.
Myth: Children younger than 3 years old can’t get tested for food allergies.
Fact: The American Academy of Pediatrics (AAP) says there is no specific age limit for food allergy testing. Infants younger than 6 months of age are not typically given skin prick allergy tests. However, it can be done safely in infants if a food allergy is suspected.
Testing in infants under 3 months old may be difficult to interpret. The raised bump indicating an allergy (called a wheal) can be smaller in infants. With infants ages 6-24 months, results are usually interpreted without difficulty.
Babies with eczema are at increased risk for developing food allergies. So, for babies with eczema, food allergy testing is considered if:
- eczema symptoms are unchanged or only slightly improve despite sticking to a treatment plan for several weeks;
- eczema flares up every time the baby eats certain food(s);
- the baby is not growing as expected.
You may come across allergy panels or at-home sensitivity tests for food allergies. These are not reliable. The Journal of Allergy and Clinical Immunology published guidelines for food allergy diagnoses. These guidelines provide recommendations based upon clinical research. The guidelines say that skin prick tests and blood tests are the only diagnostic tests that can reliably diagnose a food allergy. Allergists may also use food elimination diets or a food challenge to aid in diagnosis.
If you think your child has a food allergy, consult a board-certified allergist. They will take a full history of symptoms and recommend options for testing.
Myth: Babies should not be given allergenic foods before age 3.
Fact: For most babies, allergenic foods should be introduced into the diet at the same time as solid foods. This is usually between the ages of 4-6 months.
Three professional groups released a joint report with recommendations on food allergy. The groups are:
- American Academy of Allergy, Asthma, and Immunology (AAAAI)
- American College of Allergy, Asthma, and Immunology (ACAAI)
- Canadian Society for Allergy and Clinical Immunology
The report says parents should introduce single-ingredient foods to their child between the ages of 4-6 months. These foods can include:
- fruits (apples, pears and bananas);
- vegetables (green vegetables, sweet potatoes, squash and carrots);
- cereal grains (rice or oat cereal) one at a time.
Food can be introduced this way every 3-5 days based on the infant’s developmental readiness. This process gives parents and caregivers a chance to identify any food that causes an allergic reaction.During the same 4-6 month window, parents can introduce small portions of the following foods after a baby tolerates less allergenic foods:
- tree nuts
- fin fish
Delaying the introduction of these foods may increase your baby’s risk of developing allergies.
Important: Never give a young child a whole peanut or tree nut to eat. This is a choking hazard. Give the child peanut butter or nuts made into a puree or spread.
Researchers say introducing common allergens to babies 4-6 months of age can help them build tolerance to those allergens.
Parents of babies with severe eczema, egg allergy or both should meet with a board-certified allergist. The baby should undergo testing to determine if peanut can be safely introduced. If the allergist approves, these infants can be given peanut-containing foods between 4-6 months of age. Early introduction of peanut may reduce the baby’s risk of a peanut allergy. But it must be introduced under the supervision of an allergist.
Parents should also consult an allergist about peanut allergy if…
- the baby experiences any signs of an allergic reaction to a food;
- the baby has a sibling who is allergic to peanut.
Myth: Children with egg allergy should not get the flu shot or the MMR (measles, mumps, rubella) vaccines.
Fact: AAAAI and ACAAI recently updated guidelines for giving flu shots. The guidelines say flu shots for egg-allergic people pose no greater risk for an allergic reaction than for non-egg allergic people. A special observation period or restrictions on where shots can be given are not needed.
AAP and CDC’s Advisory Committee on Immunizations Practices (ACIP) says the MMR vaccine can be safely administered to those with egg allergies.
You may also wonder about the COVID-19 vaccine for people with egg allergies. None of the COVID-19 vaccines contain egg products. So, they are safe for people with a history of egg allergies. Watch this video about egg allergy and the flu and COVID-19 vaccines.
Myth: There is no cure or treatment for food allergy.
Fact: This is a partial truth. There is no actual “cure” for a food allergy. There are effective treatments for managing symptoms. The current standard of care for managing food allergy is avoiding the trigger food. Any signs of anaphylaxis must be treated with epinephrine.
One of the more exciting developments in food allergy treatment is oral immunotherapy. This is sometimes referred to as OIT. With OIT, people are given gradually increasing amounts of an allergen. The goal is to slowly increase the amount of the allergen needed to trigger a reaction. The only OIT currently approved by FDA is Palforzia™. Palforzia is approved for the treatment of peanut allergy. Peanut, egg and milk OIT have varying degrees of success at desensitization (60-80%).
OIT is not a cure but it does show promise. People with severe food allergies must still carry epinephrine.
Some children can outgrow food allergies. This is particularly true for egg, soy, wheat and milk allergies. About 25% of children outgrow peanut allergies by age 12. People who develop a food allergy in adulthood are unlikely to outgrow allergies.
Hopefully, this clears up some of the common misconceptions on food allergies. Key takeaways are:
- There is a difference between food allergy and food intolerance.
- An anaphylactic reaction to a food should always be treated with epinephrine. Remember, epinephrine first and epinephrine fast.
- Babies can be tested for food allergies.
- For most infants, it’s recommended that parents introduce allergenic foods between the ages of 4 and 6 months. Talk with an allergist first if your child has severe eczema, an egg allergy and/or a sibling who has a peanut allergy.
- People with egg allergies can received the flu, MMR, and COVID-19 vaccines safely.
- There is no cure for food allergies. There are effective treatments such as oral immunotherapy.
- Children can sometimes outgrow food allergies.
William E. Berger, MD, FACAAI, is a board-certified allergist and immunologist who serves as Medical Director with Allergy & Asthma Network. He is a Distinguished Fellow and Past President (2002-03) of the American College of Allergy, Asthma & Immunology (ACAAI).