What is a food allergy?
Approximately 15 million Americans suffer from food allergy, with 6.5 million allergic to seafood and 3 million allergic to peanuts or other nuts (tree nuts). A food allergy is an exaggerated immune response triggered by a food. This is caused by an allergic antibody called IgE (immunoglobulin E), which is found in people of any age with allergies.
What are the causes of food allergies?
The cause of food allergies is not fully understood. A food allergy can develop even after you have eaten a food several times in the past without ever having a problem. A food allergen is the part of the food that causes an allergic reaction. These allergens are usually proteins. Most of these allergens can cause reactions even after they are cooked or have been digested. Eight foods account for 90% of allergic reactions. These are the proteins in cow’s milk, eggs, peanuts, wheat, soy, fish, shellfish and tree nuts. 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 if they strictly avoid the offending foods when they are young. Allergies to peanuts, tree nuts and shellfish tend to be for life.
What are the symptoms of food allergies?
Food allergy symptoms usually begin immediately and seldom more than two hours after eating. The most common allergic skin reaction to a food is hives (red, itchy swollen areas of the skin). Eczema or atopic dermatitis (itchy, scaly red dry skin) can be triggered by a food allergy. Asthma (coughing, wheezing or difficulty breathing) symptoms may develop. Vomiting, diarrhea, abdominal cramping or pain and swelling of the mouth or throat are signs of gastrointestinal reactions.
Anaphylaxis is a systemic (whole body) allergic reaction that maybe life threatening and causes 30,000 emergency room visits a year. The first signs of anaphylaxis can be feeling warm and flush, tingling in the mouth or a red itchy rash. Other symptoms may include feeling lightheaded, short of breath, anxiety, stomach cramps, vomiting and diarrhea. In very severe cases, patients can have a drop of blood pressure that causes loss of consciousness and shock. Without immediate treatment, anaphylaxis may cause death. Death can be sudden and sometimes occur within minutes.
How do you diagnose a food allergy?
Allergy skin tests are helpful to determine which food, if any are causing an allergic reaction. If there is severe eczema all over the body, a blood test may be ordered to get food allergy information. A patient or parent should never try to deliberately cause a reaction or reintroduce a food on his or her own. If a food allergy is suspected, stop eating that food and see your allergy specialist or health care provider to discuss being tested and treatment options.
How is food allergy treated?
- Avoid the food completely.
- Ask about ingredients – you must ask at restaurants and others’ homes if the food you are allergic to is in a dish. Simply picking out the offending food is not safe. Just one bite of an allergy causing food can cause a reaction. Some allergens are airborne so steaming, boiling and simmering foods can cause problems without ever eating it.
- Read all food labels every time.
- Be prepared for emergencies – Anaphylactic reactions caused by food allergies can be potentially life threatening. You must carry and know how to use injectable epinephrine, antihistamines and sometimes bronchodilators to treat an accidental ingestion of a food you are allergic to. Anyone who is around the patient routinely should know how to treat those with food allergies. This could include but not limited to parents, spouses, teachers, grandparents, coworkers, babysitters and friends. Also, be careful at birthday, school, holiday and any social parties you or your child may be attending. It is a good idea to also wear a medical alert bracelet identifying the allergy. Even after treatment with medications, it is important to call 911 and go to the hospital for further treatment even if you start to feel better because the symptoms can return later.
- Educate others – Convincing others that food allergy is real is often the most challenging part of living with food allergies. If you or your child has a food allergy, share this brochure so they can better understand the precautions you must take.
Resources for further information and websites:
American Academy of Allergy, Asthma and Immunology
American College of Allergy, Asthma and Immunology
Food Allergy Research & Education