The Food Allergy and Anaphylaxis Network states that soybean allergy is one of the most common food allergies. Soy is in many processed foods, such as cereals, crackers, canned tuna, baked goods and margarine, and it goes by many names, including edamame, glycine max, hydrolyzed vegetable protein, lecithin and MSG. Soy contains proteins that can trigger allergic reactions in adults. Food allergies cause the body to release antibodies and chemicals to fight the allergen, which causes physical symptoms. While soy allergy may cause severe allergic reaction in some people, the FAAN advises that most people with soy allergy experience mild symptoms.
Gastrointestinal Upset
Mayo Clinic.com advises that food allergies cause the release of histamine in the body. Histamine release may cause diarrhea to occur as an attempt to flush the allergen from the body. You may also experience abdominal discomfort with a soy allergy. Intestinal cramping and bloating can occur in addition to diarrhea. Nausea, or the sensation of needing to vomit, and vomiting may occur after ingesting soy. The Cleveland Clinic advises that gastrointestinal upset, as well as additional symptoms of soy allergy may appear within minutes to hours after consuming a soy product.
Skin Reaction
You may develop skin reactions in response to eating a soy-containing food. Hives may develop which are red, raised, itchy patches on the skin. Hives commonly develop on the face, neck and trunk, but they may appear anywhere on the body. Tingling may develop in the mouth or on the lips upon eating soy. Some people experience facial flushing that makes the face feel hot and look red.
Severe Symptoms
Cleveland Clinic advises that some people may develop a severe allergic reaction to soy, called anaphylaxis. This type of allergy has the potential to be life threatening. Anaphylaxis occurs suddenly after soy ingestion. Symptoms of severe soy allergy include lightheadedness or dizziness due to a drop in blood pressure. You may experience swelling of the lips or mouth or feel as if your throat is constricted or swelling shut. Breathing becomes difficult and wheezing--a high-pitched, musical sound--may develop. You may feel as if your heart is racing. Anaphylaxis requires immediate medical treatment to prevent medical complications or even death.
