Like other food allergies, an oat allergy can leave you feeling ill. Symptoms can include feeling sick to your stomach, breaking out in hives, and even difficulty breathing.

Oat allergies can develop anytime from infancy to adulthood. They are more common in infancy. While a true oat allergy is not common, oat sensitivity or intolerance can also cause allergy-like symptoms.

Oat Allergy vs. Intolerance

Food allergies involve the immune system, and they are more serious than food intolerances. If you have an allergy, even eating small amounts of the triggering food can cause many symptoms, some life-threatening.

A food intolerance involves the digestive system. Symptoms include discomfort of the digestive tract (think: cramping, constipation, or diarrhea). People with a food intolerance can sometimes eat small amounts of the triggering foods. They may also be able to eat them with a digestive aid (for example, taking Lactaid when consuming dairy products).

Discovering an Oat Allergy

If you consistently react when you eat food with oats, your body might be giving you signs of an oat allergy.

Common Symptoms of an Oat Allergy

Oat allergies can cause different symptoms depending on which parts of the immune system are affected. Similar to other food allergies, common symptoms include:

• Itchy mouth, throat, and eyes
• Hives, rash, itching, and eczema
• Swelling in the lips and tongue
• Stomach pain, nausea, diarrhea, or vomiting
• A runny nose
• Wheezing
• Dizziness or fainting
• Trouble breathing
• Under severe circumstances, anaphylaxis

Anaphylaxis is a severe allergic reaction. It can be life-threatening if not addressed immediately. Anaphylaxis symptoms include:

• Low blood pressure
• Rapid heart rate
• Difficulty breathing from throat swelling or airway tightening
• Skin changes (flushed skin, rash, or swelling)
• Dizziness, lightheadedness, or fainting

If you or a loved one starts to experience symptoms of anaphylaxis, get immediate medical attention.

Diagnosing an Oat Allergy

Getting diagnosed with a food allergy involves meeting with a doctor to discuss and test for the allergy. Your doctor will want to know what types of reactions you’ve had. They’ll also ask if you’ve noticed any pattern of when the symptoms happen (like if it’s always after eating oats). Your doctor might use a few tests to help determine the cause of your allergy. These include:

• A skin prick test — Your doctor pricks your skin with a small amount of oats and watches to see if it causes a reaction (a raised, itchy spot like a bug bite).
• A blood test — A blood test can measure the level of an allergy protein in your blood.
• An elimination diet — You avoid eating oats for a while and track your symptoms.
• A food challenge — You eat a small amount of oats in the doctor’s office and see if you react.

It’s important to go through specific allergy testing to find the food you are allergic to. Sometimes during food production, cross-contamination can occur as different foods are made and packaged. This means that sometimes different allergens can end up in food that shouldn’t contain it. For example, gluten (the protein found in wheat) could potentially be found in oat products. In some cases, gluten may be what is causing your allergy, not oat.

Your doctor will help you determine the true source of your allergy and help you find ways to manage it.

Other Oat-Related Reactions

Studies have found that people with eczema have a higher rate of developing an oat sensitivity. This may happen because oats are an ingredient in some topical ointments and lotions that people with eczema may use more frequently. Your health care provider may suggest you avoid lotions and ointments with oat protein to reduce the risk of developing oat sensitivity.

Oats can also be cross-reactive with other cereal products. This means that the structure of other proteins (such as gluten in wheat) can cause a similar reaction to avenin, the protein that causes an oat allergy. In one small study of children, there was a 33 percent cross-reactivity rate. This means that 33 percent of the children with gluten sensitivity also experienced a reaction to barley and oats.

Types of Allergies

There are different types of food allergies based on which part of the immune system is affected. Immunoglobulins are antibodies that help our bodies fight against germs. With an allergy, the immune system uses these antibodies to fight against the allergen, causing an allergic reaction. Immunoglobulin-E (IgE) is typically involved with certain types of allergies. The type of allergy will determine some of the symptoms that show up, as well as how soon they show up.

IgE-Mediated Allergies

IgE-mediated food allergies typically cause symptoms in less than an hour after eating the food. Less severe symptoms include skin reactions and an upset stomach. IgE-mediated food allergies are more severe than non-IgE-mediated allergies and can lead to anaphylaxis.

Non-IgE-Mediated Allergies

Non-IgE-mediated food allergies still involve the immune system, just a different part. They are less severe and do not cause anaphylaxis. Non-IgE food allergies typically take a bit longer for symptoms to develop. They can occur a few hours to days after eating the food. A few conditions fall under this category.

An important non-IgE-mediated allergy related to oats is food protein-induced enterocolitis syndrome (FPIES). FPIES can have multiple food-related triggers, including oats. It occurs more commonly in infants but can also occur in adults.

FPIES symptoms include severe digestion issues (repetitive vomiting or diarrhea), decreased energy, and paleness. If the condition gets worse, it can lead to poor growth, dehydration, and shock. If your child shows any of these symptoms, it’s important to see a health care provider.

Living With an Oat Allergy

With any type of food allergy, you’ll need to make some lifestyle changes to ensure you stay safe and avoid your allergen.

Oat Allergy Management

Once you’re diagnosed with an oat allergy, it’s important to learn which foods contain oats. When you eat out, take a few extra steps to make sure the food is safe for you to eat. When grocery shopping, check food labels for words and phrases like “oats,” “avenin,” “may contain oats,” and “manufactured in a facility that uses oat ingredients.”

Foods to avoid include:

• Oats
• Granola
• Muesli
• Oat milk
• Oat flour

Other items that may contain oats include:

• Baked goods
• Cereals
• Beer
• Granola bars
• Nutrition bars

These lists are not all-inclusive, but they give you a good idea of items to start looking out for to help manage your allergy. If you have any specific questions about foods, be sure to contact a dietitian, an allergist, or your primary care doctor.

Oat Allergy Treatment

There’s no cure for food allergies. However, sometimes kids outgrow allergies. There isn’t a lot of data for oat-specific allergy. One study found that about 40 percent of kids with rice as an FPIES trigger outgrew the condition by the age of 3.

Some medications can help manage oat allergy symptoms. Antihistamines can help with less severe reactions. Epinephrine is the medication for severe allergic reactions, including anaphylaxis. Epinephrine can be administered at a hospital or with a portable auto-injector. People with severe allergies often carry an epinephrine auto-injector, such as an EpiPen or Auvi-Q, that can be used in an emergency.

Talking with your doctor is the best option to find out how severe your oat allergy is and what medications would best help you manage it.

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Are you or a loved one living with an oat allergy? Have you found helpful ways to manage it? Share your experience in the comments below, or start a conversation by posting on your Activities page.