Food Allergies

	Topic Overview
	Health Tools
	Cause
	Symptoms
	What Happens
	What Increases Your Risk
	When To Call a Doctor
	Exams and Tests
	Treatment Overview
	Prevention
	Home Treatment
	Medications
	Surgery
	Other Treatment
	Other Places To Get Help
	Related Information
	References
	Credits

Is this topic for you?

This topic has general information about food allergies. If you would like more specific information about peanut allergy, see the topic Peanut Allergy.

What is a food allergy?

When you have a food allergy, your body thinks certain foods are trying to harm you. Your body fights back by setting off an allergic reaction. In most cases, the symptoms are mild—a rash, a stuffy nose, or an upset stomach. A mild reaction is no fun, but it is not dangerous. A serious reaction can be deadly. But quick treatment can stop a dangerous reaction.

Allergies tend to run in families. You are more likely to have a food allergy if other people in your family have allergies like hay fever, asthma, or eczema (atopic dermatitis).

Food allergies are more common in children than adults. About 7 out of 100 kids have them. Only about 2 out of 100 adults do.¹ Children often outgrow their food allergies. But if you have a food allergy as an adult, you will most likely have it for life.

What are the symptoms?

Food allergies can cause many different symptoms. They can range from mild to serious. If you eat a food you are allergic to:

• Your mouth may tingle, and your lips may swell.
• You may have cramps, an upset stomach, or diarrhea.
• You may have itchy skin with red, raised bumps called hives .
• You may have a stuffy nose, wheeze, or be short of breath.
• You may feel dizzy or lightheaded.

Kids usually have the same symptoms as adults. But sometimes a small child just cries a lot, vomits, has diarrhea, or does not grow as expected. If your child has these symptoms, see your doctor.

Some people have symptoms after eating even a tiny bit of a problem food. As a rule, the sooner the reaction begins, the worse it will be.

The most severe reaction is called anaphylaxis (say “ANN-uh-fuh-LAK-suss”). It affects your whole body. Anaphylaxis usually starts within an hour after you eat the food, and the symptoms can come back 1 to 2 hours later. If you have anaphylaxis:

• Your throat and tongue may swell quickly.
• You may suddenly start wheezing or have trouble breathing.
• You may feel sick to your stomach or vomit.
• You may feel faint or pass out.

Anaphylaxis can be deadly. If you have (or see someone having) any of these symptoms, call 911 right away.

What foods most often cause a food allergy?

A few foods cause most allergies. A food that causes an allergy is called a food allergen. Usually it is the protein in a food that causes the problem.

• Eggs, milk, peanuts, wheat, soy, and fish cause most problems in children. Most kids outgrow allergies to milk, wheat, eggs, and soy by the time they are 5. But kids rarely outgrow an allergy to peanuts or fish.
• Peanuts, tree nuts (like walnuts or almonds), fish, and shellfish cause most problems in adults.

If you are allergic to one food, you may also be allergic to other foods like it. So if you are allergic to peanuts, you may also be allergic to soybeans or peas.

How is a food allergy diagnosed?

Your doctor will ask questions about your medical history and do a physical exam. Your doctor will also ask what symptoms you have. He or she may want you to write down everything you eat and any reactions you have.

If your doctor thinks you could have a serious food allergy, you may have a skin test. The doctor will put a little bit of liquid on your skin and then prick your skin. The liquid has some of the possible food allergen in it. If your skin swells up like a mosquito bite, your doctor knows you are allergic to that food. Your doctor may also do blood tests to look for the chemicals in your blood that cause an allergic reaction.

How is a food allergy treated?

The best treatment is to never eat the foods you are allergic to. Learn to read food labels and spot other names for problem foods. For example, milk may be listed as "caseinate," wheat as "gluten," and peanuts as "hydrolyzed vegetable protein." When you eat out or at other people’s houses, ask about the foods you are served.

If you do eat a food you are allergic to, medicines can help. You may be able to stop a mild reaction by taking over-the-counter antihistamines. You may need prescription medicines if over-the-counter drugs do not help or if they cause side effects, such as making you feel sleepy.

If you have severe food allergies, your doctor will prescribe an allergy kit that contains epinephrine (say "eh-puh-NEH-fren") and antihistamines. An epinephrine shot can slow down or stop an allergic reaction. Your doctor can teach you how to give yourself the shot.

You can have symptoms again even after you give yourself a shot. So go to the emergency room every time you have a severe reaction. You will need to be watched for at least 4 hours after the reaction.

If you have had a serious reaction in the past, your chance of having another one is high. Be prepared.

• Keep an allergy kit with you at all times.
• Wear a medical alert bracelet to let others know about your food allergy.
• Check the expiration dates on the medicines in your kit, and replace them as needed.

My child has a food allergy. What else should I think about?

Talk to your child’s school and caregivers. They should know how to keep problem foods away from your child. Teach them what to do if your child eats one of these foods by mistake.

If your child has ever had a severe reaction, keep an allergy kit nearby at all times. Some kids carry their kit in a fanny pack. Have your child wear a medical alert bracelet. Teach all caregivers to act quickly. They should:

• Know the signs of a severe reaction.
• Know how to give an epinephrine shot.
• Call 911 right away.

How is a food allergy different from a food intolerance?

Many people think they have a food allergy, but in fact they have a food intolerance. Food intolerance is common. It can cause some of the same symptoms as a mild food allergy, like an upset stomach. But a food intolerance does not cause an allergic reaction. A food intolerance can make you feel bad, but it is not dangerous. A serious food allergy can be dangerous.

If you are not sure which you have, it is a good idea to see your doctor.

Frequently Asked Questions

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	Giving a child an epinephrine shot
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Food allergies occur when the body's immune system overreacts to substances in food you have eaten, triggering an allergic reaction. Food allergies are more common in young children than in adults. This may be because children's immune and digestive systems are not completely developed.²

• Eggs, milk, peanuts, wheat, soy, and fish cause most of the allergic reactions in children. Some babies are so sensitive to these foods that if the offending food is eaten by the mother, drinking her breast milk can cause a reaction. Most children outgrow allergies to milk, wheat, eggs, and soy between ages 3 and 5. Children rarely outgrow an allergy to peanuts or fish.
• Peanuts, tree nuts such as walnuts or almonds, fish, and shellfish cause most of the allergic reactions in teens and adults. Adults generally remain allergic to the food for life.

Food allergies are most common in people who are atopic, meaning they have an inherited tendency to develop allergic conditions. These people are more likely to have asthma, various allergies, and a skin condition called atopic dermatitis.

If you are highly sensitive to a particular food, you may have an allergic reaction by simply being near the food. Flying in airplanes where other passengers are eating peanuts or simply eating in a seafood restaurant may cause symptoms.

The more common a food is, the more likely it is that people will be allergic to it. For example, rice allergy is seen in Japan, and codfish allergy is seen in Scandinavia. As foods from around the world have become more available, the number of allergic reactions to exotic fruits such as kiwi and papaya and to seeds such as sesame seeds and poppy seeds have increased.

Because peanuts are used in so many foods, peanut allergy has increased in the United States in the past two decades and is now a major cause of severe allergic food reactions. Peanut allergy is usually lifelong and tends to become more severe over time. For more information, see the topic Peanut Allergy.

Celiac disease is caused by an allergy to a protein (gluten) found in wheat and some other grains. For more information, see the topic Celiac Disease.

Cross-reactivity

Many people are allergic to foods that are similar or somehow related. This is called cross-reactivity. For example, if you are allergic to shrimp, you may also be allergic to other shellfish, like crab or lobster. If you are allergic to peanuts, you may be allergic to other members of the legume family, such as peas and beans.

Oral allergy syndrome is a type of cross-reactivity. In this syndrome, people who have pollen allergies (such as a grass allergy) may develop itching, redness, and swelling of the lips and mouth when they eat fruits or vegetables that contain a protein that reacts with the pollen. These symptoms usually resolve quickly and do not involve other body parts.

Oral allergy syndrome occurs with the following pollens and foods:^{3, 4}

A growing number of people, especially health care workers, are discovering they have an allergy to latex. Latex is the natural sap of the rubber tree. It is used in making surgical gloves, condoms, balloons, and other products. If you have a latex allergy, you may also have allergies to kiwis, passion fruit, papayas, bananas, avocados, figs, peaches, nectarines, plums, tomatoes, celery, and chestnuts.

Other concerns

In rare cases, symptoms of a severe, life-threatening allergic reaction (anaphylaxis) can occur following vigorous exercise. This is called exercise-induced anaphylaxis. In some people, it happens only after they eat specific foods to which they are allergic. It can produce itching, lightheadedness, hives, difficulty breathing, and other serious symptoms. The offending food does not cause a reaction without exercise, and, alternately, exercise does not cause a reaction unless you eat the food first.

Sulfites, which are present as a food additive, often cause difficulty breathing in people who have asthma. Sulfites are used in wines, dried fruits, and some soda pop, among other foods.

Symptoms of food allergy can affect many parts of your body, including your:

• Digestive system. Symptoms include stomach cramps, nausea, vomiting, diarrhea, itching in the mouth and throat, and rectal bleeding (rare in adults). These symptoms occur more frequently in children than in adults.
• Skin. Symptoms include hives or welts, swelling, itching, redness, and atopic dermatitis. Skin reactions are common in children.
• Respiratory system. Symptoms include coughing; wheezing; an itchy, stuffy, runny nose; sneezing; and difficulty breathing.

Children usually have the same symptoms as adults. Symptoms of milk or soy allergies in children may include eczema, runny nose, and wheezing. However, sometimes the only symptoms are extreme crying (colic), vomiting, blood in the stool, diarrhea, constipation, or poor growth.

Symptoms vary in severity from mild to life-threatening and can appear from within minutes to days of eating a food. The most severe reaction is anaphylaxis, which affects many body systems and can result in death. Anaphylaxis usually occurs minutes to an hour after you eat the food and can reoccur 1 to 2 hours later. Common triggers for anaphylaxis are peanuts, nuts, and seafood; in children, peanuts cause anaphylaxis more often than other foods.^{3, 5} Aspirin, exercise, or alcohol can increase the risk for anaphylaxis.³

Symptoms may be more severe if you also have another type of allergy, such as an allergy to pollens or mold. Tobacco smoke, stress, and colds can also make symptoms worse.

There are many other conditions with similar symptoms, such as food poisoning and inflammatory bowel disease.

The first time you eat a food that triggers an allergic reaction, your body's immune system recognizes the food as a foreign substance (allergen). Your body reacts by developing antibodies against the food. When you eat the offending food again, the antibodies attack the allergen, releasing histamine and other chemicals that cause the symptoms of an allergic reaction.

Symptoms often develop within minutes, although they may not be apparent for an hour or more. In some cases, symptoms may not develop for days. In general, the sooner the reaction begins, the more severe it will be.

Symptoms may start with tingling and swelling of the mouth and tongue. When the food allergen enters the stomach and intestines, cramping, nausea, vomiting, and diarrhea can develop. Symptoms may occur throughout the body when the food allergen is absorbed from the digestive system into the bloodstream.

In moderate reactions, the body reacts with hives and itching, wheezing, nasal congestion, and possibly dizziness or lightheadedness. Most of the symptoms of a moderate allergic reaction subside in a few hours once antihistamine medication is taken or the food allergen leaves the body. However, a skin rash (atopic dermatitis) may persist for several weeks.

In severe reactions, the body releases larger amounts of histamine and other chemicals that can cause life-threatening anaphylaxis. This may happen in a few minutes to an hour. Symptoms of anaphylaxis usually subside quickly after epinephrine and antihistamines are given. Epinephrine, which is given as a shot, stops the further release of the chemicals that cause a severe reaction and counteracts the symptoms.

You have a greater chance of developing food allergies if you:

• Have a family history of allergy. Food allergies are most common in people who are atopic, meaning they have an inherited tendency to develop allergic conditions such as asthma, various allergies, and atopic dermatitis. If both of your parents have allergies, you have about a 75% chance of developing allergies.⁶
• Have another allergic condition such as atopic dermatitis or asthma.
• Are young. Infants and children have more food allergies than adults.
• Have a medical condition that makes it easier for allergens to pass through the walls of the stomach and intestines and enter the bloodstream. These conditions include gastrointestinal disease, malnutrition, prematurity, and diseases that impair the immune system.

You have a greater risk for a life-threatening allergic reaction (anaphylaxis) from food allergy if you:

• Have asthma.
• Develop allergy symptoms within minutes of eating the food.

If you or your child has a severe food allergy, always carry an allergy kit and know how to use it. You should also wear a medical alert bracelet at all times. Being prepared to immediately deal with a severe allergic reaction decreases the risk of death.

Call 911 or other emergency services immediately if you have had a severe reaction in the past from the same food and similar symptoms are developing. If you have an allergy kit prescribed by your doctor for severe allergic reactions, give yourself the epinephrine shot before you call for help. If possible, have someone else call while you give yourself the shot.

Since symptoms can develop again even after the injection, go to the emergency room every time you have a reaction, even if you are feeling better. You should be observed for 4 to 8 hours after the reaction.

Call 911 or other emergency services immediately if you have any of the following symptoms:

• Rapid swelling of the throat or tongue
• Difficulty breathing, wheezing, or deep cough; a pale face or blue lips or earlobes
• Signs of shock, including:
  • Lightheadedness or a feeling that you are about to pass out
  • Restlessness, confusion, or a sense of impending doom
  • Moist, cool skin or possibly profuse sweating
  • Weakness, thirst, nausea, or vomiting
• Faintness

If you witness a severe allergic reaction and the person becomes unconscious, call 911 or other emergency services immediately.

If your food allergy symptoms are getting worse, call your doctor. It is important to identify which foods are to blame so that you can avoid them.

Watchful Waiting

If your food allergy symptoms do not get worse or are not too severe or bothersome, you can try eliminating suspect foods from your diet to see whether symptoms disappear.

Who To See

The following health professionals may evaluate and treat mild food allergies:

• Family medicine physician
• Pediatrician
• Internist
• Nurse practitioner
• Physician assistant

An allergy specialist may be needed when:

• You need to identify the foods that trigger allergic reactions.
• Your work or school performance or quality of life is affected because of allergy symptoms or medication side effects.
• You have other medical conditions, such as recurrent asthma.

You may also be referred to other specialists, such as a:

• Dermatologist, to treat allergic skin problems.
• Pulmonary specialist, when moderate or severe asthma is also present.

A nutritionist or registered dietitian can help you maintain a balanced diet even when some foods must be eliminated. A nutritionist or dietitian can also help you learn how to avoid hidden allergens in foods and give you ideas about how to make substitutions in recipes.

To prepare for your appointment, see the topic Making the Most of Your Appointment.

To diagnose a food allergy, your doctor will start with a medical history and a physical exam. Your doctor will ask detailed questions about your symptoms and how soon they begin after you eat a suspected food. It is important to determine whether you have a food allergy or food intolerance. Your doctor may ask you to keep a record of all the foods you eat and any reactions.

Your doctor may ask you to try an elimination diet, an oral food allergy challenge, or both.

• In an elimination diet, you do not eat groups of foods that likely cause allergic reactions or specific foods based on your history and other tests. If the symptoms go away when you do not eat the food, the food is suspect. If the symptoms come back when you eat the food again, it may confirm that the food is causing the allergy. The diet usually lasts for 10 to 14 days.
• In an oral food allergy challenge, you eat increasing amounts of both suspect and nonsuspect foods while being observed. Your doctor watches to see if and when a reaction occurs. If you have reactions only to the suspect foods and not to the others, the diagnosis can be confirmed. This test usually is the best way to determine whether a food allergy exists.

You may also have allergy tests. These include:

• Skin tests. A liquid containing an allergen is put on the top layer of skin, and the skin is pricked. If the skin reacts with a raised itchy area (called a wheal), it usually means that you are allergic to that allergen. Skin tests are quick, simple, and relatively safe, but results can be false-positive, meaning you do not have an allergy even though results indicate that you do. If you are extremely allergic, skin testing cannot be used.
• Radioallergosorbent test (RAST). A blood sample is taken from a vein and tested for immunoglobulin E (IgE) antibodies, which are produced in response to particular allergens. RAST may be done instead of or along with a skin test. RAST is more expensive, the results are not usually available for at least a week, and it can also give false-positive results.

Food allergy tests that are not helpful or are unproven include:³

• IgG₄ antibody.
• Provocation/neutralization.
• Cytotoxicity.
• Applied kinesiology.

The best treatment for food allergies is to avoid the food that causes the allergy. When that is not possible, you can use medications such as antihistamines for mild reactions and the medications in an allergy kit for serious reactions.

It's important to take special care with children who have food allergies. A child with severe food allergies may have a life-threatening anaphylactic reaction to even a tiny amount of a food allergen. Your child should always wear a medical alert bracelet and carry an allergy kit. Make sure that all caregivers (school administrators, teachers, friends, coaches, and babysitters):

• Know about your child's food allergy.
• Can recognize the symptoms of a food allergy.
• Know where the allergy kit is kept and how to give the epinephrine shot.
• Know to call 911 immediately.

Children may have only mild symptoms in the first few minutes after they eat the food allergen, but they may develop severe symptoms in 10 to 60 minutes. Children always should be observed in a hospital for at least 4 hours after a reaction.

Initial treatment

Initial treatment for a food allergy consists of identifying the food that causes the allergy and learning how to deal with both mild and serious reactions.

The most effective treatment for food allergies is to avoid the food in any form. Tell your family, friends, and coworkers that you have a food allergy, and ask them to help you avoid the food. Read all food labels, and learn the other names that may be used for food allergens. For example, milk may be listed as "caseinate," eggs as "albumin," wheat as "gluten," and peanuts as "hydrolyzed vegetable protein."

If your baby has a milk or soy allergy, your doctor may suggest changing the formula or breast-feeding exclusively. Specially prepared formulas are available for infants with soy and milk allergies.

If you or your child has mild allergies, nonprescription antihistamines may control the symptoms. You may need prescription antihistamines if nonprescription antihistamines don't help or if they cause bothersome side effects, such as drowsiness.

If you have a severe allergic reaction, your initial treatment may be administered in an emergency room or by emergency personnel. You will be given a shot of epinephrine to stop the further release of histamine and to relax the muscles that help you breathe. You will then be prescribed an allergy kit that contains a syringe of epinephrine and antihistamine tablets. Your doctor or pharmacist will teach you how to give yourself a shot. You will always need to have an allergy kit with you. You should also wear a medical alert bracelet or other jewelry that lists your food allergies. You can order medical alert jewelry through most pharmacies or on the Internet.

For more information about the shot, see:

Giving an epinephrine shot.

Allergy kits with doses appropriate for children are available. Children at risk of a severe allergic reaction should keep kits at school or day care as well as at home. Be sure your child's school administrator, teachers, and friends know about the food allergy. They should be trained to give the shot and call 911 immediately. Older, mature children should be taught to give themselves the shot. For more information, see:

Giving a child an epinephrine shot.

Ongoing treatment

Ongoing treatment involves continuing to avoid foods that cause allergies and being aware of any new foods that cause symptoms. Continue to inform those with whom you have regular contact about the allergy and ask them to help you avoid the food. Read food labels, and be aware that sometimes food allergens are called by other names on food labels.

Talk to your doctor about the best medications for your allergy. Make sure you always have medications available.

If you have severe food allergies, always wear medical alert jewelry that lists the foods you are allergic to. You can order medical alert jewelry through most pharmacies or on the Internet.

If your doctor has prescribed an allergy kit, always carry it with you. It contains a syringe of epinephrine and antihistamine tablets. Be sure to check the expiration dates on the medications and replace them as needed.

Give the epinephrine shot as soon as you or your child suspects a problem food has been eaten or feels a reaction starting. Then take the antihistamines. Since symptoms can develop again even after the shot, go to the emergency room every time you have a reaction, even if you are feeling better. You will need to be observed for at least 4 hours after the reaction.

For more information on the shot, see:

Giving an epinephrine shot.

Giving a child an epinephrine shot.

Children at risk for severe allergic reactions should keep allergy kits at school or day care as well as at home. Be sure your child's school administrator, teachers, and friends know about the food allergy and how to recognize the symptoms. They should be trained to give the shot and to call 911 immediately. Older, mature children should be taught to give themselves the shot.

Treatment if the condition gets worse

If your food allergy symptoms get worse, talk to your doctor. You may need an allergy kit or new medication.

Explain to family, friends, and those with whom you have regular contact that your symptoms are getting worse and that it is important for them to understand what to do if you have a severe reaction.

Continue to avoid foods that cause allergies, and be aware of any new foods that cause symptoms. Read all food labels, and make sure you know the other names that food allergens are sometimes given on food labels.

If you have severe food allergies, always wear medical alert jewelry that lists the foods you are allergic to. You can order medical alert jewelry through most pharmacies or on the Internet.

If your doctor has prescribed an allergy kit, always carry it with you. It contains a syringe of epinephrine and antihistamine tablets. Be sure to check the expiration dates on the medications and replace them as needed.

Give the epinephrine shot as soon as you or your child feels a reaction starting. Then take the antihistamines. Since symptoms can develop again even after the injection, go to the emergency room every time you have a reaction, even if you are feeling better. You will need to be observed for at least 4 hours after the reaction.

For more information on the shot, see:

Giving an epinephrine shot.

Giving a child an epinephrine shot.

Children at risk of severe allergic reactions should keep allergy kits at school or day care as well as at home. Make sure your child's teachers, school administrators, babysitters, and friends understand the danger of a severe allergic reaction. Anyone who comes in regular contact with your child should be taught to recognize the symptoms of a severe reaction, how to give the shot, and to call 911 immediately. Older, mature children should be taught to give themselves the shot.

Food allergies often occur in people who have a family history of asthma, atopic dermatitis, or allergies to pollen, mold, or other substances. These people are said to be atopic, meaning they have an inherited tendency to develop allergic conditions. Allergies cannot be prevented in these people.

The American Academy of Pediatrics recommends that all babies, especially those with a strong family history of allergies, be breast-fed for the first year of life or longer.⁷ If your baby is at high risk for allergies and you cannot breast-feed, try a hydrolyzed milk formula. The milk protein in hydrolyzed formulas is changed to try to prevent allergies.⁸

Other recommendations for high-risk babies include the following:⁷

• Nursing mothers should eliminate peanuts and tree nuts, such as almonds and walnuts, from their diet and should consider eliminating eggs, cow's milk, and fish.
• Solid foods should not be introduced into the diet of high-risk infants until they are 6 months of age. Dairy products should be delayed until 1 year, eggs until 2 years, and peanuts, nuts, and fish until 3 years of age. This may help reduce the risk of food allergies.³
• Pregnant women do not need to exclude foods from their diets, with the possible exception of peanuts.

Since tobacco smoke contributes to allergy sensitivity, it is important to have a smoke-free environment.

About 85% of children outgrow allergies to milk, wheat, eggs, and soy between ages 3 and 5.³ Children usually do not outgrow allergies to peanuts, tree nuts (such as walnuts and almonds), fish, and shellfish.

Knowing which foods trigger food allergies and avoiding those foods is the best way to prevent allergic reactions. Unfortunately, food allergens are often "hidden" in sauces, ice creams, baked goods, and other items. If you have food allergies, read food labels carefully. Be aware of other names for food allergens, such as "caseinate" for milk or "albumin" for eggs. Many people think that seeing "nondairy" on a label means there is no milk in the product. This is not necessarily true.

Occasionally products are recalled when food ingredients are missing from food labels. For a list of recalled products, see the U.S. Food and Drug Administration's Recalls, Market Withdrawals, and Safety Alerts page at http://www.fda.gov/opacom/7alerts.html.

Eating out can be dangerous for people with severe food allergies. Here are some tips:

• Bring safe substitutes from home. For example, bring soy milk to have with cereal.
• Be aware of possible cross-contamination. For example, an ice cream scoop may have been used for Rocky Road ice cream, which contains peanuts, and then used for your vanilla ice cream.
• Alert the wait staff to the possibility of a severe food reaction. Carefully question them about ingredients. If they are not sure, ask to speak to kitchen staff.
• Always wear medical alert jewelry that lists your food allergies. Medical alert jewelry can be ordered through most pharmacies or on the Internet.

If you or your child has ever had a severe allergic reaction, always carry an allergy kit that contains a syringe of epinephrine and antihistamine tablets. Give the epinephrine shot as soon as you or your child feels a reaction starting. Then take the antihistamine. For more information about the shot, see:

Giving an epinephrine shot.

Giving a child an epinephrine shot.

If you are traveling to another country, learn the words for the foods that trigger your allergy so that you can ask in restaurants and read food labels. Call airlines, tour operators, and restaurants beforehand to explain your food allergy and request safe meals. Prepare your own food when possible. Discuss your travel plans with your doctor.

Medication is used to treat some food allergies. Medications to treat a severe allergic reaction or an anaphylactic reaction are packaged in a prescribed allergy kit.

For mild allergic reactions, people often try nonprescription medications first. You can try prescription medications if nonprescription medications fail to control allergy symptoms or cause drowsiness or other bothersome side effects.

Medication Choices

Medications used to treat a severe allergic reaction include:

• Epinephrine. Epinephrine is given as a shot. It acts quickly to stop the further release of histamine and to relax the muscles that help you breathe.
• Antihistamines. Antihistamines block the action of histamine during an allergic reaction and reduce the severity of symptoms such as itching and sneezing.
• Corticosteroids. These medications help reduce inflammation.

Medications used to relieve mild food allergy symptoms include:

• Antihistamines and corticosteroids for hives, gastrointestinal symptoms, or sneezing and a runny nose.
• Bronchodilators for asthma symptoms. Bronchodilators relax the airways of the lungs, making it easier to breathe.

What To Think About

Medicines that treat symptoms of food allergies can have side effects. They are typically used for short periods and are discontinued once symptoms are resolved. The best way to avoid symptoms is to avoid the food you are allergic to. Read all food labels, and be aware that sometimes food allergens are called by other names on food labels.

There is no medicine that you can take before eating a certain food that will reliably prevent an allergic reaction to that food.

Allergy shots (desensitization therapy) for food allergies are considered experimental and are not recommended.

A recent small study of a medicine for peanut allergy showed promising results. The medicine, called an anti-IgE drug, binds to the antibodies (IgE) released during an allergic reaction to peanut.⁹ A larger study is under way to find out whether this medicine is safe and effective for people who have peanut allergies.

There is no surgical treatment for food allergies.

New treatment options under investigation for food allergies include:³

• Injecting antibodies against immunoglobulin E (IgE). These antibodies are able to reduce allergic reactions.
• Immunotherapy (allergy shots or desensitization therapy), which helps your body become less sensitive to substances that you are allergic to.
• Vaccination with a genetic substance specific to a food allergen.
• Using substances that change how the immune system reacts to an allergen (immunomodulators).

Experimental therapies such as neutralization, ingesting dilute forms of the food allergen to "neutralize" allergic reactions, and cromolyn, a medication commonly used for allergic rhinitis, have not proven effective.

Organizations

• Allergic Reaction
• Allergic Rhinitis
• Asthma in Children
• Asthma in Teens and Adults
• Atopic Dermatitis
• Lactose Intolerance
• Rash, Age 11 and Younger
• Rash, Age 12 and Older

Citations

1. Burks AW (2003). Food allergies. In DC Dale, DD Federman, eds., Scientific American Medicine, section 6, chap. 16. New York: WebMD.

2. Sampson HA (2002). Food allergies. In M Feldman et al., eds., Gastrointestinal and Liver Disease, 7th ed., vol. 2, pp. 1983–1993. Philadelphia: W.B. Saunders.

3. Sicherer SH (2002). Food allergy. Lancet, 360(9334): 701–710.

4. American Academy of Allergy, Asthma, and Immunology (2000). Food reactions. In Allergy Report, vol. 3. Available online: http://www.aaaai.org/ar/working_vol 3/069.asp.

5. Coomer TA (2002). Allergic reactions. In FD Burg et al., eds., Gellis and Kagan's Current Pediatric Therapy, vol. 17, pp. 953–954. Philadelphia: W.B. Saunders.

6. Wilson SH (2000). Medical nutrition therapy for food allergy and food intolerance. In LK Mahan, S Escott-Stump, eds., Food, Nutrition, and Diet Therapy, 8th ed., pp. 912–934. Philadelphia: W.B. Saunders.

7. Committee on Nutrition, American Academy of Pediatrics (2000). Hypoallergenic infant formulas. Pediatrics, 106(2): 346–349.

8. Osborn DA, Sinn J (2004). Formulas containing hydrolysed protein for prevention of allergy and food intolerance in infants. Cochrane Database of Systematic Reviews (4). Oxford: Update Software.

9. Leung DYM, et al. (2003). Effect of anti-IgE therapy in patients with peanut allergy. New England Journal of Medicine, 348(11): 986–993.

Other Works Consulted

• Al-Muhsen S, et al. (2003). Peanut allergy: An overview. Canadian Medical Association Journal, 168(10): 1279–1285.

• Burks AW (2003). Food allergies. In DC Dale, DD Federman, eds., Scientific American Medicine, section 6, chap. 16. New York: WebMD.

• National Institute of Allergy and Infectious Diseases (1999). Food allergy and intolerances. Health Matters. Bethesda, MD: National Institutes of Health. Available online: http://www.niaid.nih.gov/factsheets/food.htm.

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Author:	Lila Havens	Last Updated May 26, 2005
Medical Review:	Martin Gabica, MD - Family Medicine Kathleen Romito, MD - Family Medicine Jerome B. Simon, MD, FRCPC, FACP - Gastroenterology
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