Related Medical Conditions

Some medical conditions can produce symptoms similar to those of food allergies. Learn more about eosinophilic esophagitis, celiac disease and more.

Itchy mouth, swollen throat, vomiting.… These symptoms can be caused by more than just food allergies.

The disorders described below may produce symptoms like those of food allergies. However, some do not involve IgE (immunoglobulin E), the antibody that causes potentially life-threatening reactions in people with food allergies.

It is possible for a person to have both a food allergy and a related condition, such as eosinophilic esophagitis or oral allergy syndrome.

Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) results when large numbers of eosinophils, a type of white blood cell, gather in the esophagus (the tube that connects the mouth to the stomach). As a result, the lining of the esophagus becomes inflamed, making it difficult for food to go down. Certain foods can trigger EoE.

Symptoms vary, depending on age. With infants and toddlers, families often note feeding difficulties, irritability and poor weight gain. Older children typically have regurgitation (spitting up), vomiting, heartburn and belly pain. Teenagers and adults may have chest pain, difficulty swallowing and a feeling that food “gets stuck” when they swallow.

Some people with EoE complain that it takes a long time to eat meals. They’ll also say they need large amounts of water to help swallow their food. They may complain of feeling full rapidly and stop eating before finishing a meal.

Food allergy testing can help determine if a food is triggering EoE.

To learn more about EoE, please visit the American Partnership for Eosinophilic Disorders.

Food Protein-Induced Enterocolitis Syndrome

Food protein-induced enterocolitis syndrome (FPIES) is a serious, non-IgE-mediated type of food allergy. FPIES is usually triggered by cow’s milk or soy. Other foods may also cause it, especially the cereal grains rice and oat.

FPIES symptoms typically include severe vomiting and diarrhea. Reactions tend to happen two to three hours after eating the trigger food.

Medical professionals do not use standard food allergy tests for diagnosing FPIES. The primary test that can diagnose this disease is an oral food challenge. Often, FPIES resolves by age three.

To learn more about FPIES, please visit the FPIES Foundation and the International FPIES Association.

Oral Allergy Syndrome

Oral allergy syndrome (OAS), also known as pollen-food syndrome, refers to itchy or scratchy mouth symptoms caused by raw fruits or vegetables. It occurs in people who also have hay fever.

OAS happens when people who are allergic to pollen eat raw fruits or vegetables that have proteins similar to pollens. This triggers an allergic response when the food is eaten. Because these proteins are sensitive to heating, most people affected by OAS can eat cooked fruits or vegetables.

Symptoms are usually limited to the mouth. They usually go away minutes after the food is swallowed or removed from the mouth. Treatment generally is not necessary.

OAS typically presents in older children, teens or young adults. Its onset can be sudden, often after patients have been eating the offending foods without problems for many years.

Common pollen-food associations

Not every individual allergic to pollen develops symptoms with cross-reacting fruits or vegetables. You may react to a few but not all of these foods.

  • Birch: apple, carrot, peach, plum, cherry, pear, almond, hazelnut
  • Grasses: tomato
  • Ragweed: melons, zucchini, cucumber, kiwi, banana

Food Intolerances

Except celiac disease, food intolerances do not involve the immune system. Although food intolerances may cause some of the same symptoms as a true food allergy, they cannot trigger anaphylaxis. Here are two of the most common:

Lactose Intolerance
Lactose intolerance occurs when a person’s small intestine does not produce enough of the lactase enzyme. As a result, affected individuals are not able to digest lactose, a type of sugar found in dairy products.

The symptoms typically occur within 30 minutes to two hours after ingesting dairy products. Large doses of dairy may cause increased symptoms.

Many people confuse lactose intolerance with milk allergy. Learn more about the differences.

Celiac Disease
Celiac disease, or celiac sprue, is an adverse reaction to the protein gluten. Gluten is found in wheat, rye, barley and sometimes oats, which may come into contact with grains that contact gluten. People with celiac disease must strictly avoid these grains and their by-products for the rest of their lives.

When people with this digestive disease eat gluten, they experience an immune reaction in the small intestine. IgE, the antibody responsible for life-threatening reactions (anaphylaxis), does not play a role in this disorder. However, the immune response in celiac disease may damage the lining of the small intestine. This prevents the body from properly absorbing the nutrients in food. Over time, patients may become malnourished.

Celiac disease symptoms include bloating and gas, diarrhea, constipation, headaches, itchy skin rash and pale mouth sores. The symptoms may vary among affected individuals.

Many people confuse celiac disease with gluten intolerance and wheat allergy. Learn more about the differences.

To learn more about celiac disease, please visit the Celiac Disease Foundation and Beyond Celiac.