IgE-mediated food allergy

What it is: Your body makes antibodies, or proteins, called immunoglobin E (IgE), in response to a new food or ingredient. The next time you encounter the food or ingredient, the IgE antibodies set off your immune system. This causes an allergic reaction, usually within one to two hours. It’s possible to have a reaction up to eight hours later.

Who’s affected: About 4% of U.S. children and adults have IgE-mediated food allergies. Most allergies appear in early childhood, but they can appear at any age.

Symptoms:

• Hives
• Swelling in the face, throat or other body parts
• Stomach pain
• Nausea and vomiting

If your symptoms are:

• Mild: Take an antihistamine (Allegra, Benadryl, Claritin). Symptoms usually go away within a day.
• Sudden and severe, with trouble breathing: Get emergency care. Symptoms can take a few days to go away.

Diagnosis: We’ll talk with you about your history of symptoms. This is our best tool for diagnosing a food allergy. We may do a skin-prick or blood test to confirm the diagnosis. Our doctors and nurses are trained to help children and adults through this process.

If needed, we may do a food challenge in our clinic, exposing you to the food in small steps.

Food protein-induced enterocolitis (FPIES)

What it is: A reaction to a food protein that causes the intestines to swell (inflammation). Symptoms usually appear one to four hours after eating.

Who’s affected: FPIES affects mostly babies and children under 5. It can affect adults.

Symptoms in babies and children:

• Repeated or severe vomiting
• Diarrhea
• Dehydration
• Feeling weak and tired
• Loss of color
• In some cases, a drop in blood pressure

Symptoms in adults:

• Diarrhea one to four hours after eating (delayed diarrhea)
• Cramplike pain in the belly

If your symptoms are:

• Mild:  Drink fluids to stay hydrated.
• Severe: Get medical care.

Evaluation: We may do tests to see if something else is causing symptoms. We may do a food challenge in our clinic, exposing you to the food in small steps.

Eosinophilic esophagitis (EoE)

What it is: A chronic (ongoing) condition that damages the esophagus, the food pipe that connects the throat and stomach. In this condition, white blood cells called eosinophils build up inside the esophagus. This can hurt the tissue or cause it to swell.

Who’s affected: You are more likely to develop EoE if you have:

• Food or seasonal allergies
• Acid reflux (when stomach acid rises into the esophagus)

Symptoms:

• Trouble swallowing
• Food getting stuck in the esophagus
• Chest pain or heartburn
• Vomiting
• Slow growth or slow weight gain in children

If your symptoms are:

• Mild: We may have you try a special diet or medication.
• Serious: We may do a procedure that stretches your esophagus.

Evaluation: We may do blood tests. You may see a gastroenterologist, a digestive-system doctor, to:

• Look at your esophagus in a procedure called an upper endoscopy. It uses a tiny camera at the end of a flexible tube.
• Do a biopsy. During the endoscopy, the doctor takes out a bit of tissue for study.

Oral allergy syndrome (pollen-food allergy syndrome

What it is: The immune system reacts to nuts and fresh fruits and vegetables that have proteins similar to pollen proteins. People with this allergy can usually eat the foods cooked with no symptoms.

Who’s affected: People with pollen allergies.

Symptoms:

• Itchy or tingly mouth or throat
• In some cases:
  • Rash or redness
  • Swelling in the face
  • Vomiting

If your symptoms are:

• Mild: You usually don’t need treatment.
• Serious: You may need to carry epinephrine (EpiPen).

Evaluation: We do a skin-prick or blood test to confirm a pollen allergy.