Soy
Allergy Facts, Symptoms, and Treatment

An inexpensive source of vegetable protein for millions of people, soybeans are legumes native to East Asia that also contain thiamin, riboflavin, iron, phosphorus, magnesium, calcium, zinc, and vitamin B6.1,2,3 Also known as soya beans and soja beans, soybeans are consumed as whole beans, as flour, and in oil.1,4 Plus, during food manufacturing, they're used as texturizers, emulsifiers, and protein fillers, and they're utilized as animal feed and as ingredients in hundreds of chemical products.1,2,4 Common elements in Asian cuisine, soybeans and their derivatives are found in a multitude of processed foods including infant formulas, canned broths, canned tuna, processed meats, baked goods, and energy bars.5

Among the top eight food allergens in the United States, soy is a self reported allergen in an estimated 1.5 percent of Europe s population, and it represents a common allergen among children.2,3,6 While 0.4 percent of children in the United States have a soy allergy, most outgrow it by the age of 10.3

Where is soy found?

Employed as whole beans, flour, and oil, soybeans are used in a vast variety of ways. Among them, soybean flour is often added to other flours for baking, and the majority of breads contain some soy flour. Plus, soy is fermented to create soy and Worcestershire sauces, and it's used to manufacture tofu, which in turn is integrated into products such as soy based ice cream.4 While young soybeans (aka edamame) are often boiled or steamed and eaten independently, soybean seeds are a source of oil, which is then incorporated into a host of items including salad dressings, margarine, baby food, linoleum, paint, and soap.1,4 In addition, soybeans can be processed to create textured vegetable protein (TVP), which is integrated into simulated meat products and added to meat.

Given the prevalence of soy in processed foods, it's very difficult to avoid, and it's particularly hard to identify because it may be added as a compound ingredient. For example, a food product might contain margarine, and its product label will list the butter alternative. However, if the margarine contains soy, soybean likely will not be listed on the ingredient panel.4

The following foods may contain soy:2,4 artificial cheese, baby food and infant formula, baked goods, black pudding, bread (especially high protein varieties), breakfast cereals, burger patties, butter substitutes (e.g., margarine), candy, canned meat and tuna, canned fish in sauce, Chinese food, chocolates (particularly the creamy centers), cooking oils, crackers, desserts, gravy powders, hot dogs, ice cream, liquid meal replacers, meat products (e.g., sausage, pastes), muesli, pies, powdered meal replacers, salad dressings, sauces (e.g., Worcestershire, sweet and sour, teriyaki), shortenings, snack bars, soups (including canned and packaged), soy pasta products, soy sauce, soy sprouts, soybeans, stews, stock cubes (bouillon cubes), tempeh, tofu, Tofutti, and TV dinners.

The following ingredients, which can appear on food labels, may contain soybean protein:4 bulking agent, carob, emulsifier, guar gum, gum arabic, hydrolyzed vegetable protein (HVP), lecithin, miso, monosodium glutamate (MSG), protein, protein extender, soy flour, soy nuts, soy panthenol, soy protein, soy protein isolate or concentrate, soy sauce, soybean oil, stabilizer, starch, textured vegetable protein (TVP), thickener, vegetable broth, vegetable gum, and vegetable starch.

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Are there other allergens I could be sensitized to?*

Some people with soybean allergy may also experience symptoms when eating other seemingly unrelated foods. This is called cross-reactivity and occurs when your body's immune system identifies the proteins, or components, in different substances as being structurally similar or biologically related, thus triggering a response. The most common cross-reactivities with soybeans are fruits (e.g., apple, cherry), vegetables (e.g., carrot), legumes (e.g.,peanut), seeds, and tree nuts.

If you experience an itchy mouth or throat after eating soy containing products or other related fresh fruits or raw vegetables, you may suffer from Oral Allergy Syndrome (OAS), sometimes called Pollen Food Allergy Syndrome (PFAS).9 This condition is also caused by your immune system's reaction to similar proteins, or components, found in plant foods and tree pollens. It is quite common, with up to 25 percent of children with allergic rhinitis (i.e., hay fever) also suffering from OAS when eating fruits or vegetables.12 Common pollen allergies that could cause OAS when eating soy containing products include tree pollens (e.g., birch, alder, and hazel).2

Do I need to avoid all forms of soy?

Soy consists of different types of proteins that all have different characteristics that may be associated with varying risk of causing severe allergic reactions. Some people with soy allergy may be able to eat soy if it is extensively heated (cooked), as high temperatures break down the causative proteins. For another patient, soy should be avoided completely, as it could potentially cause a severe event, also called anaphylaxis. Your specific risk profile depends on which proteins you are allergic to.2

Knowing the proteins, or components, within each allergen that are triggering your symptoms can help guide your management plan. With that in mind, and based on your symptom history, your healthcare provider may suggest something called a specific IgE component test, which can help reveal other pollens and foods you may react to.2

Already have your specific IgE component test results?

Your component test results will include the name of the components (a series of letters and numbers and/or name). Your healthcare provider will likely review the results with you, but here you'll find an at-a-glance breakdown you can use as a reference. Simply match the component names to the list below to see what they mean in terms of symptom management.2

rGly m 4

  • Usually associated with mild symptoms, e.g., OAS, when ingesting mildly processed soy products, but also sometimes severe reactions, due to birch pollen allergy (cross-reactivity).
  • Sensitive to heat and digestion, cooked foods are often tolerated.

nGly m 5, nGly m 6

  • Symptoms are likely caused specifically by soy.
  • Usually associated with severe reactions. 
  • Stable to heat and digestion, both cooked and raw foods may cause symptoms.

MUXF3 (CCD)

  • Positive specific IgE for soy in combination with MUXF3 CCD (Cross-Reactive Carbohydrate Determinant) being the only positive component test indicates that the cause of symptoms may be something other than soy.

Test results should be interpreted by your healthcare provider in the context of your clinical history. Final diagnosis and decision on further management is made by your healthcare provider.

*These products may not be approved for clinical use in your country. Please work with your healthcare provider to understand availability.

How do I manage my allergy?

Because there is no cure for food allergies, your healthcare provider may recommend a plan that includes the following.13-17

  • Read ingredient labels and "may contain" advisory panels on food and nonfood products carefully, and avoid all foods and products containing any form of the allergen. Note that these lists and panels may not appear on the same side of a product's packaging and that manufacturers frequently change ingredients. If you're unable to obtain a list of ingredients, it's safest to avoid that item.
  • Avoid cross-contamination when cooking by using two sets of cooking and eating utensils, with one exclusively for the allergic individual. Wash all dishes and utensils in hot soapy water between uses.
  • Craft an action plan with a list of steps for you and others to take should you accidentally ingest the allergen. Print out a copy of the plan and carry it with you.
  • Talk with restaurant chefs about your allergy and order food that's simply prepared and void of any form of the allergen. Avoid desserts, as they often contain or have come into contact with food allergens.
  • Plan ahead for traveling to ensure your food allergy will be managed and any emergency medication is always available.
  • Wear a medical ID bracelet identifying the allergen to which you're allergic.
  • Carry any recommended or emergency medication with you at all times.
  • Teach children with food allergies which foods to avoid. Work with caregivers and school staff to eliminate or reduce exposure to the allergen and to ensure they understand when and how to use medication to treat symptoms.

Your healthcare provider may direct you to take one of the following medications:

  • Epinephrine auto-injector when there are signs of an acute severe event, aka anaphylaxis (see below). Ensure your family members know how to administer it in case of an emergency.
  • Antihistamines as a supplement may be useful in relieving mild symptoms (e.g., itch); however, they do not halt the progression of an allergic reaction.
  • Bronchodilator (albuterol) as a supplemental therapy for respiratory symptoms, especially in those with a history of bronchospasm or asthma.

If you're with someone who's having an allergic reaction and shows signs of shock, act fast. Look for pale, cool, and clammy skin; a weak, rapid pulse; trouble breathing; confusion; and loss of consciousness. Do the following immediately:

  • Call local emergency services.
  • Ensure the affected individual is lying down with legs elevated.
  • Administer epinephrine immediately for any obvious signs of anaphylaxis.
  • Check the affected individual's pulse and breathing and administer CPR or other first-aid measures if necessary.

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Soy Allergen Facts, Symptoms, and Treatment

Common Symptoms

Soy allergy can range from mild to severe and may vary over time, resulting in mild symptoms during one episode and severe symptoms in another. Although food allergy symptoms can start a few minutes to several hours after ingestion, most begin within two hours.7 Symptoms may involve the skin, gastrointestinal tract, cardiovascular system, and respiratory tract, and may include one or more of the following:7,8

  • Abdominal pain, diarrhea, nausea, vomiting, stomach cramps
  • Hives (allergic urticaria), itching, eczema
  • Wheezing, nasal congestion, shortness of breath, repetitive cough
  • Shock, circulatory collapse
  • Tight, hoarse throat, trouble swallowing
  • Pale or blue skin coloring
  • Dizziness, lightheadedness, fainting, weak pulse
  • Anaphylaxis, a potentially life-threatening event

Symptoms may also include the following, which are associated with Oral Allergy Syndrome (OAS), aka Pollen Food Allergy Syndrome (PFAS).9

  • Itchy mouth and hives on the mouth
  • Scratchy throat
  • Swelling of the lips, mouth, tongue, and throat
  • Itchy ears

How do I know if I'm allergic?*

Together with your symptom history, skin-prick testing or specific IgE blood testing can help determine if you are allergic to a particular allergen. If you are diagnosed with an allergy, your healthcare provider will work with you to create a management plan.

It's important to note that some children with soy allergy may outgrow their allergy, and food can be reintroduced. Therefore, periodic retesting and oral food challenges are recommended to track any progress toward outgrowing soy allergy.10,11

*These products may not be approved for clinical use in your country. Please work with your healthcare provider to understand availability.

Is there a risk for a severe event?

Because food allergic reactions are unpredictable and symptoms range from local to systemic, it is recommended that an epinephrine prescription be considered for any patient with an IgE-mediated food allergy.13

If you have asthma, you may face a higher risk of severe soy reactions, particularly if your asthma is poorly controlled.14

  1. Encyclopedia Britannica [Internet]. Chicago: Encyclopedia Britannica Inc.; 2019 Nov 1. Available from: https://www.britannica.com/plant/soybean.
  2. EAACI, et al. Molecular allergology user's guide. Pediatr Allergy Immunol. 2016 May;27 Suppl 23:1-250. doi: 10.1111/pai.12563. PMID: 27288833. (225-234 p.) Available from: http://www.eaaci.org/documents/Molecular_Allergology-web.pdf.
  3. Kids with Food Allergies [Internet]. Arlington, VA: Asthma and Allergy Foundation of America; 2015 Feb. Available from: https://www.kidswithfoodallergies.org/soy-allergy.aspx.
  4. Steinman HA. Hidden allergens in foods. J Allergy Clin Immunol. 1996;98:241-50.
  5. American College of Allergy, Asthma & Immunology [Internet]. Arlington Heights, IL: American College of Allergy, Asthma & Immunology; 2014 [2019 Apr 9]. Available from: https://acaai.org/allergies/types/food-allergies/types-food-allergy/soy-allergy.
  6. Nwaru BI, Hickstein L, Panesar SS, Roberts G, Muraro A, Sheikh A; EAACI Food Allergy and Anaphylaxis Guidelines Group. Prevalence of common food allergies in Europe: a systematic review and meta-analysis. Allergy. 2014 Aug;69(8):992-1007. doi: 10.1111/all.12423. Epub 2014 May 10. PMID: 24816523.
  7. American College of Allergy, Asthma & Immunology [Internet]. Arlington Heights, IL: American College of Allergy, Asthma & Immunology; 2014. Available from: https://acaai.org/allergies/types/food-allergy.
  8. Mayo Clinic [Internet]. Rochester, MN: Mayo Foundation for Medical Education and Research; 2019 Nov 2. Available from: https://www.mayoclinic.org/diseases-conditions/food-allergy/symptoms-causes/syc-20355095.
  9. American College of Allergy, Asthma & Immunology [Internet]. Arlington Heights, IL: American College of Allergy, Asthma & Immunology; 2014. Available from: https://acaai.org/allergies/types/food-allergies/types-food-allergy/oral-allergy-syndrome.
  10. Abrams EM, Sicherer SH. Diagnosis and management of food allergy. CMAJ. 2016 Oct 18;188(15):1087-1093. doi: 10.1503/cmaj.160124. Epub 2016 Sep 6. PMID: 27601605; PMCID: PMC5056872.
  11. Savage JH, Kaeding AJ, Matsui EC, Wood RA. The natural history of soy allergy. J Allergy Clin Immunol. 2010 Mar;125(3):683-6. doi: 10.1016/j.jaci.2009.12.994. PMID: 20226303.
  12. Roberts, Graham & Xatzipsalti, M & Borrego, Luis & Custovic, Adnan & Halken, Susanne & Hellings, Peter & Papadopoulos, Nikolaos & Rotiroti, G & Scadding, Glenis & Timmermans, Frans & Valovirta, Erkka. (2013). Paediatric rhinitis: Position paper of the European Academy of Allergy and Clinical Immunology. Allergy. 68. 10.1111/all.12235.
  13. Wright BL, Walkner M, Vickery BP, Gupta RS. Clinical Management of Food Allergy. Pediatr Clin North Am. 2015 Dec;62(6):1409-24. doi: 10.1016/j.pcl.2015.07.012. Epub 2015 Sep 7. PMID: 26456440; PMCID: PMC4960977.
  14. The Anaphylaxis Campaign [Internet]. Farnborough, UK: The Anaphylaxis Campaign; 2018 Jun. Available from: https://www.anaphylaxis.org.uk/wp-content/uploads/2019/07/Soya-2018.pdf.
  15. American College of Allergy, Asthma & Immunology [Internet]. Arlington Heights, IL: American College of Allergy, Asthma & Immunology; 2014. Available from: https://acaai.org/allergies/types-allergies/food-allergy/food-allergy-avoidance.
  16. Harvard Health Publishing [Internet]. Boston, MA: Harvard Medical School; 2020. Available from: https://www.health.harvard.edu/healthbeat/6-tips-for-managing-food-allergies.
  17. Mayo Clinic [Internet]. Rochester, MN: Mayo Foundation for Medical Education and Research; 2019 Sep 14. Available from: https://www.mayoclinic.org/diseases-conditions/anaphylaxis/symptoms-causes/syc-20351468.
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