Food allergy Health Article

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:

• Abdominal pain
• Diarrhea
• Difficulty swallowing
• Itching of the mouth, throat, eyes, skin, or any area
• Light-headedness or fainting
• Nasal congestion
• Nausea
• Runny nose
• Swelling (angioedema), especially of the eyelids, face, lips, and tongue
• Shortness of breath
• Stomach cramps
• Vomiting

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.