Food Allergies | Digestive Health Program | Loyola Medicine

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Food Allergies

Overview and Facts about Food Allergies

A food allergy is a digestive health condition in which exposure to a certain food triggers a harmful immune response. According to the CDC, the number of people with food allergies is rising. It is estimated that about 15 million Americans have some kind of food allergy, including nearly six million under age 18. Approximately, 30 percent of children with food allergies are allergic to multiple foods.

Symptoms and Signs of Food Allergies

Some people just experience discomfort during an allergic reaction, but for others, an allergic reaction can be extremely alarming. Signs and symptoms of food allergies typically develop between a few minutes to two hours after eating the food and can include:

  • A tingling or itching sensation in the mouth
  • Abdominal pain, diarrhea, nausea, vomiting or another digestive health issue
  • Congestion and wheezing that creates difficulty in breathing
  • Dizziness, lightheadedness or fainting
  • Hives, eczema or incessant itching
  • Swelling of the lips, face, tongue and throat, or other parts of the body

Causes and Risk Factors of Food Allergies

A food allergy is caused by the immune system mistaking a specific food or substance as something harmful. The immune system releases antibodies that go after the food or substance. So the next time you eat even a small bite, the antibodies will sense it and the immune system will fight back.

Causes of allergic food reaction tend to differ between adults and children. In adults, the majority of food allergies are triggered by certain proteins in:

  • Fish
  • Peanuts
  • Shellfish, including shrimp, lobster or crab
  • Tree nuts, such as walnuts and pecans

Meanwhile, in children, food allergies are commonly triggered by proteins in:

  • Cow's milk
  • Eggs
  • Peanuts
  • Tree nuts
  • Soy
  • Wheat

In the most severe cases, a food allergy can cause a severe allergic reaction called anaphylaxis. This can cause potentially deadly reactions, including:

  • A severe drop in blood pressure
  • A swollen throat, or the feeling that a lump in your throat is blocking your breathing
  • An elevated pulse
  • Dizziness, lightheadedness or loss of consciousness
  • Shock

Risk factors for developing food allergies include age, family history or whether or not you have another allergy or asthma.

Tests and Diagnosis of Food Allergies

Diagnosing a food allergy is very complicated. Food allergy testing can provide some insight into the symptoms, but it cannot conclusively determine whether the cause of the symptoms is a food allergy.

To try and make a diagnosis, the doctor will ask you about the history of your symptoms and amount of certain foods you have been consuming. A blood test can determine whether the antibodies are present in the body.

Treatment and Care for Food Allergies

The only way to prevent a food allergy attack is to avoid the food altogether. In the event that you accidentally consume the dangerous food, treatment will depend on the reaction's severity. Mild symptoms can be treated with antihistamines, while more serious reactions like anaphylaxis require a shot of epinephrine immediately.