What is food allergy?

Before discussing food allergy diagnosis and treatment, it’s best to first know what food allergy is. Food allergies occur when your body’s immune system identifies certain food proteins as harmful.

Your immune system produces antibodies to combat what it perceives to be a foreign substance, which triggers the response.

This allergic reaction can cause inflammation of the gastrointestinal tract, with symptoms such as abdominal pain, diarrhea and vomiting; swelling of the respiratory tract, which can also lead to choking; skin rash and itching; and anaphylaxis, a life-threatening loss of blood pressure.

Causes of food allergy

About 90 percent of all food allergies are caused by a handful of foods, including cow’s milk, peanuts, wheat-based foods, fish and shellfish. A recent research paper found that people with peanut and milk allergies were more likely to be hospitalized.

When determining if a reaction to food is actually an allergy, we first check family history. If a sibling or another close relative has a food allergy, eczema, asthma or rhinitis (irritation and inflammation of the mucous membrane inside the nose), it greatly increases the possibility of a food allergy.

Potential risk for allergic food reactions is greater at a younger age; such reactions occur in 6 to 8 percent of children under age 5, as opposed to a rate of 1 to 3 percent among adults.

Treatment options

After getting a history, we conduct a series of tests – a skin test, blood test and, finally, the “gold standard” test, the food challenge. These tests are both open and blinded. If the patient “passes,” or doesn’t experience a reaction during any of these tests, he or she doesn’t have a food allergy. In general, we can clear a vast majority of patients who are misdiagnosed as having “food allergy.”

For those who do test positive for food allergy, the most logical advise is to avoid the suspected foods and carry emergency medications, including EpiPen^® (injectable epinephrine), if required. Several promising therapies for food allergy, including food desensitization, are in various stages of development. They should become available to food allergy sufferers in central Wisconsin in the near future.

Learn more about allergies and asthma.