It's not common to be allergic to oats, although it can happen. Oats aren't always the issue, though. Sometimes other ingredients or contaminants can be the actual sources of allergic responses. If you experience negative side effects after eating oatmeal, call your doctor. Symptoms can be life-threatening in some cases.
One of the first things you might notice if you're allergic to oats is red, blotchy spots on your skin. They can occur on your hands after touching oats, around your mouth after eating oats or anywhere else on your body that comes into contact with the allergen. Red patches can pop up in other areas, too, like around your eyes as oatmeal works its way through your digestive tract. These skin irritations can be itchy and crusty and could be associated with hives.
Cold and Flu-Like Symptoms
Sometimes an allergy makes you feel like you have a cold or the flu. Shortly after eating your steamy bowl of oatmeal, your nose may start running. A dry cough, sneezing and nasal congestion could soon follow. You might even have a dry, itchy mouth or itchy ears. An oatmeal allergy may also give you a bellyache and affect your digestive tract, making you nauseated, causing vomiting or leaving you with diarrhea.
If your lips, tongue or throat start to swell up, your oat allergy is probably more severe. Swelling lets you know that your immune system is going into overdrive, attacking the proteins in oatmeal it deems dangerous. If you start wheezing, turn blue, have difficulty breathing or have pain in your chest, seek immediate medical attention. You might be going into anaphylactic shock, which can lead to loss of consciousness, a weak pulse and even death.
Ingredients in prepared oatmeal other than the oats may be the actual culprits. Take dairy, for example. Some restaurants add milk to oatmeal to give it a more creamy texture. The allergic side effects you're experiencing could be from the dairy, not from the oats. Or sometimes gluten intolerance leads to gastrointestinal issues that resemble an allergy, if the oats were contaminated with gluten. If your oats are not labeled as "gluten-free" and you have celiac disease, you might experience some intestinal issues. Read labels or ask about ingredients if someone else is preparing your oatmeal so you can work with your doctor to figure out if oats are the real problem.