For most people, soy allergy is uncomfortable but not serious. Rarely, an allergic reaction to soy can be frightening and even life-threatening. Signs and symptoms of a food allergy usually develop within a few minutes to hours after eating a food containing the allergen.
Soy allergy symptoms can include:
- Tingling in the mouth
- Hives; itching; or itchy, scaly skin (eczema)
- Swelling of lips, face, tongue and throat, or other body parts
- Wheezing, runny nose or breathing difficulty
- Abdominal pain, diarrhea, nausea or vomiting
- Skin redness (flushing)
A severe allergic reaction (anaphylaxis) is rare with a soy allergy. It's more likely to occur in people who also have asthma or who are allergic to other foods besides soy, such as peanuts.
Anaphylaxis causes more-extreme signs and symptoms including:
- Difficulty breathing, caused by throat swelling
- Shock, with a severe drop in blood pressure
- Rapid pulse
- Dizziness, lightheadedness or loss of consciousness
When to see a doctor
See your primary care doctor or a doctor who specializes in treating allergies (allergist) if you experience food allergy symptoms shortly after eating. If possible, see your doctor during an allergic reaction.
Seek emergency treatment if you develop signs or symptoms of anaphylaxis, such as:
- Difficulty breathing
- Rapid, weak pulse
- Dizziness or lightheadedness
- Drooling and inability to swallow
- Full-body redness and warmth (flushing)