Soy Allergies: Symptoms, Prevention & Treatment

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Soy Allergies

Soy products come from processed soybeans and are among the top eight food allergies in children. Most people show signs of having a soy allergy as babies when exposed to soy-based formula. Many will outgrow the allergy in early childhood, according to, but not all. A recent study showed 69 percent of children outgrow the allergy by the age of 10, as reported by the American Academy of Allergy, Asthma & Immunology. Some older children and adults, however, can develop an allergy to soy. Soy can be found in numerous products, including cereal, sauces, soups, and baked goods.


Soy allergy symptoms are similar to other food allergies. Though usually mild, any food allergy can cause anaphylaxis, which requires immediate medical care. The following symptoms can occur with allergies to soy when it is eaten:

  • Diarrhea, vomiting, abdominal pain
  • Itching in the throat, around the mouth, or anywhere
  • Congestion
  • Runny nose
  • Sneezing
  • Coughing
  • Wheezing, shortness of breath
  • Swelling in the lips, eyes
  • Asthma attack
  • Lightheaded, fainting
  • Difficulty swallowing

If any of these symptoms occur, have a health care provider perform a skin allergy test or blood test to confirm that soy was the trigger.


Preventing allergic reactions to soy requires diligently reading food labels. Soy can be listed in a number of ways, including:

  • Edamame
  • Tofu
  • Miso
  • Tempeh
  • Tamari
  • Soya
  • Soy flour, fiber, milk, protein

If a food contains any soybean products, don’t eat it. Many packages will highlight whether a food contains a known allergen or if it was made in a processing plant where the allergen is processed. Ask at restaurants or whenever you eat food someone else prepared if it contains any soy products. Caregivers or teachers should be informed of the soy allergy to aid in pevention.


While no medication can cure soy allergies, some medications can help during an allergic reaction. Antihistamines can reduce symptoms of an allergic reaction to soy. If the reaction causes an asthma attack, a bronchodilator can be used. Anyone with a soy allergy, or any other food allergy, should carry an EpiPen or epinephrine shot at all times and wear a medical alert bracelet. If the soy causes anaphylactic shock, the epinephrine should be given as soon as possible, followed by immediate medical care. Signs of anaphylaxis include similar symptoms as the initial allergic reaction, but can become severe and include further symptoms, such as low blood pressure, increased heart rate, and cardiac arrest.

References Food Allergies

American Academy or Allergy, Asthma & Immunology: Kids with Allergy to Soy–What Are the Odds They’ll Outgrow It

Children’s Mercy Hospital and Clinics: Soy Allergy

University of Maryland Medical Center: Food Allergy Soy Allergy