Wentworth-Douglass Hospital
(603) 742-5252
Decrease (-) Restore Default Increase (+) font size
Physicians
Site Search

Food guide pyramid
Food guide pyramid


Anaphylaxis
Anaphylaxis


Food allergies
Food allergies


Read food labels
Read food labels


Dermatitis, perioral
Dermatitis, perioral


Antibodies
Antibodies


Definition:

A food allergy is an exaggerated immune response triggered by eggs, peanuts, milk, or some other specific food.



Alternative Names:

Allergy to food



Causes, incidence, and risk factors:

Normally, your body's immune system defends against potentially harmful substances, such as bacteria, viruses, and toxins. In some people, an immune response is triggered by a substance that is generally harmless, such as a specific food.

The cause of food allergies is related to your body making a type of allergy-producing substance called immunoglobulin E (IgE) antibodies to a particular food.

Although many people have a food intolerance, food allergies are less common. In a true food allergy, the immune system produces antibodies and histamine in response to the specific food.

Any food can cause an allergic reaction, but a few foods are the main culprits. In children, the most common food allergies are to:

  • Eggs
  • Milk
  • Peanuts
  • Shellfish (shrimp, crab, lobster, snails, clams)
  • Soy
  • Tree nuts
  • Wheat

A food allergy frequently starts in childhood, but it can begin at any age. Fortunately, many children will outgrow their allergy to milk, egg, wheat, and soy by the time they are 5 years old if they avoid the offending foods when they are young. Allergies to peanuts, tree nuts, and shellfish tend to be lifelong.

In older children and adults, the most common food allergies are:

  • Fish
  • Peanuts
  • Shellfish
  • Tree nuts

Food additives -- such as dyes, thickeners, and preservatives – may rarely cause an allergic or intolerance reaction.

An oral allergy syndrome may occur after eating certain fresh fruits and vegetables. The allergens in these foods are similar to certain pollens. Examples are melon/ragweed pollen and apple/tree pollen.

Many Americans believe they have food allergies, while in reality fewer than 1% have true allergies. Most people's symptoms are caused by intolerances to foods such as:



Symptoms:

Symptoms usually begin immediately, within 2 hours after eating. Rarely, the symptoms may begin hours after eating the offending food.

If you develop symptoms shortly after eating a specific food, you may have a food allergy. Key symptoms include hives , hoarse voice, and wheezing .

Other symptoms that may occur include:

Symptoms of oral allergy syndrome:

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


Signs and tests:

In severe reactions, you may have low blood pressure and blocked airways.

A blood or skin test can be done to identify elevated antibody levels (particularly IgE) and confirm that you have an allergy.

With elimination diets, you avoid the suspected food until your symptoms disappear. Then the foods are reintroduced to see if you develop an allergic reaction.

In provocation (challenge) testing, you are exposed to a suspected allergen under controlled circumstances. This may be done in the diet or by breathing in the suspected allergen. This type of test may provoke severe allergic reactions. Challenge testing should only be done by a doctor.

Never try to deliberately cause a reaction or reintroduce a food on your own. These tests should only be performed under the guidance of a health care provider -- especially if your first reaction was severe.

See: Allergy testing



Treatment:

The only proven treatment for a food allergy is to avoid the food. If you suspect you or your child has a food allergy, consult an allergy specialist.

If you have symptoms on only one area of the body (for example, a hive on the chin after eating the specific 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 provide some relief.

Consult your doctor if you think you have had an allergic reaction to food, even if it is only a local reaction.

Anyone diagnosed with a food allergy should carry (and know how to use) injectable epinephrine at all times. If you develop any type of serious or whole-body reaction (even hives) after eating the offending food, inject the epinephrine. Then go to the nearest hospital or emergency facility, preferably by ambulance. Seek immediate medical attention after injecting epinephrine for a food reaction.



Support Groups:

Food Allergy and Anaphylaxis Network -- www.foodallergy.org



Expectations (prognosis):

Avoiding the offending foods may be easy if the food is uncommon or easily identified. However, you may need to severely restrict your diet, carefully read all package ingredients, and ask detailed questions when eating away from home.



Complications:

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

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



Calling your health care provider:
  • 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 doctor 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 evaluated by an allergy specialist.


Prevention:

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

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



References:

Lack G. Clinical practice. Food allergy. N Engl J Med. 2008;359:1252-1260.




Review Date: 4/23/2009
Reviewed By: Stuart I. Henochowicz, MD, FACP, Associate Clinical Professor of Medicine, Division of Allergy, Immunology, and Rheumatology, Georgetown University Medical School. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
adam.com


Find What You Need

Events
Careers
Foundation
About Us
Contact
Directions
News
Social Media Agreement
Joint Notice
Web Privacy Policy
WDH Staff Portal

Centers & Services

Cancer Center
Cardiovascular Care
Joint Replacement
Women & Children's
Physician Offices
Other Services

Conditions & Treatments

Health Information
Ebola Information

Support Services

Support Groups
Care-Van
Dental Center
Social Work
Food & Nutrition
Integrative Wellness
Spiritual Care
Concerns & Grievances
Homecare and Hospice

For Patients

Pay Your Bill Online
Pricing Estimates
Financial Assistance
Interpreter Services
Surgery Preparation
Medical Record Request
Advance Directives
Clinical Research & Trials

For Healthcare Professionals

Work and Life
Financial Well-Being
Career and Growth

The Wentworth-Douglass Health System includes:

 

Address

Wentworth-Douglass Hospital
789 Central Avenue, Dover, NH 03820
Phone: (603) 742-5252
Toll free: 1 (877) 201-7100