Wheat allergy is an allergic reaction to foods containing wheat. Allergic reactions can occur from eating wheat and by inhaling wheat flour. Wheat can be found in many foods, including some you might not suspect, such as beer, soy sauce and ketchup. Wheat allergy sometimes is confused with celiac disease, but these conditions differ. A wheat allergy generates an allergy-causing antibody to proteins found in wheat. In people with celiac disease, a protein in wheat or gluten causes an abnormal immune system reaction. Medications may be necessary to manage allergic reactions if you accidentally eat wheat.