Legume Allergy: Peanut, Soy, Lupin, Chickpea and Cross-Reactivity
Allergy to peanut, soy, lupin, chickpea, lentil and pea explained: how often legumes cross-react, what studies and allergy bodies say, labeling rules, and emergency signs.
Content last updated . This page has not been medically reviewed.
Peanuts, soybeans, lupin, chickpeas, lentils and peas are all legumes, plants in the same big family. That is why people ask whether an allergy to one means an allergy to all. The short, honest answer from the research is: sometimes, but less often than the lab tests suggest. This guide shows the numbers we read, which legumes matter most and what to do about labels and emergencies. It is information, not medical advice. Only an allergist can tell you what is safe for you.
Read this first
- Emergency: if someone has trouble breathing, swelling of the face, tongue or throat, a sudden widespread rash, repeated vomiting, dizziness or collapse after eating, treat it as anaphylaxis. The FDA says to stop eating the food, consider using emergency medicine such as epinephrine, and seek medical care. [1] Call 911 (or your local emergency number). See food allergy basics and emergency signs.
- Peanut and soy are both major allergens in the US, along with milk, eggs, fish, shellfish, tree nuts, wheat and sesame. The FDA requires them to be named on labels. [1]
- Lupin is not a US major allergen, but must be named in the ingredient list. It is a major allergen to declare in the EU. [2] [3] [4]
- Being sensitized is not the same as being allergic. In a 2023 study, peanut-allergic patients were often sensitized to lupine (70%) but only 16.7% were actually allergic to it. [7]
- Do not guess which legumes to avoid. The Dutch authors say blinded food challenges are needed to confirm or exclude co-allergy, so ask an allergist which legumes to test, avoid or try under supervision. [7]
Why legumes cross-react
Cross-reactivity means the immune system sees similar proteins in two foods. In the 2023 study, co-sensitization between legumes was mainly due to proteins called 7S and 11S globulins, with 2S albumins playing a smaller part. [7] Inhibition tests there showed green pea and lentil co-sensitization was largely cross-reactivity (79% to 90% inhibition), while peanut and lentil cross-reactivity was limited. [7] A French study of 27 legume-allergic children found that a cowpea (black-eyed pea) extract strongly inhibited IgE binding to pea and peanut extracts, which points to shared proteins. [10] The Dutch study had small groups (9 to 30 patients) and used routine clinic records, and it was funded by a research council in Finland through a food-protein project. [7]How often: what studies found
| Group studied | Finding | Source |
|---|---|---|
| 195 French children with peanut allergy | 63.9% were sensitized to at least one other legume (fenugreek 66.3%, lentil 42.2%, soy 39.9%, lupine 34.2% of those tested). 27.9% of the sensitized children (34 of 122) had confirmed allergy to another legume. Lentil, lupine and pea were the main culprits, and half of the reactions to non-peanut legumes were severe. [9] | Muller et al., 2022 |
| Dutch patient groups | Peanut- and soy-allergic patients rarely had clinical allergy to other legumes (16.7% or less). About 63.3% of soy-allergic patients were also allergic to peanut. Green pea, lupine, lentil and bean-allergic patients more often also had peanut or soy allergy. [7] | Smits et al., 2023 |
| Peanut allergy and lupin | Sources give widely different numbers: about 15 to 20% sensitized, 28% reacted in a French challenge and 4% in a UK study. [6] The AAAAI says skin tests show cross-reactivity in up to 44%, and clinical reactions in about 5 to 37% depending on the study. [3] | Soller 2018; AAAAI 2026 |
| Canadian children with pea anaphylaxis (68) | 19.1% who met strict criteria reported reactions to other legumes, mostly green pea and lentil. 38.5% also had peanut allergy. [8] | Chua and Chan, 2022 (review) |
| Spanish children with a legume allergy (44; 39 challenged) | Over 80% were sensitized to lentil, chickpea and pea, and 82.1% (32 of 39) reacted to two or more legumes in food challenges. [8] | Chua and Chan, 2022 (review) |
| Canadian children (115, social media survey) | 94.8% had peanut allergy, 15.7% soy allergy and 13.0% emerging legume allergy. No child had an emerging legume allergy alone. [13] | Cosyns et al., 2022 |
Why the numbers jump around: the groups differ (place, age, how allergy was confirmed), and tests often show sensitization that does not cause symptoms. The Chua and Chan review says soy sensitization with peanut correlates poorly with clinical cross-reactivity. [8]
Each legume
Peanut. Peanut is a legume, not a tree nut. For the food itself, see peanuts. The FDA lists peanuts as a major allergen. [1]Soy. Soybeans are a major allergen. [1] In the Dutch study, many soy-allergic patients also had peanut allergy (63.3%), but the study reports that peanut- and soy-allergic patients rarely reacted to other legumes. [7] See soy foods and tofu. Soy flour, soy protein and soy milk are all soy; check soy flour and textured soy protein.
Lupin (lupini). The FDA says lupin is a legume in the peanut family, reactions can be severe and life-threatening, people with peanut allergy face the highest risk, and some lupin-allergic people are not allergic to peanuts. [2] Lupin flour is increasingly used in baked goods and pasta, especially gluten-free products. [2] The AAAAI lists beverages sold as milk or soy alternatives, bread, pasta, sauces, hummus and vegetarian sausage among foods that may contain it, sometimes undeclared. [3] Anaphylaxis UK says you do not automatically need to avoid lupin if you have peanut allergy, because only a small number are also allergic. [4] A Canadian case report describes anaphylaxis to lupine flour in a pancake mix in a 10-year-old with peanut allergy. [6] More on the bean itself: lupini beans.
Chickpea, lentil, pea. These are the common "emerging" legume allergies in the Mediterranean area and India, according to an Italian pediatric allergy society review (2024). [12] In a London study of 203 children, non-priority legumes made up 6.3% of food allergies, with lentil the most common, and only 2.2% (lentil), 4.9% (chickpea), 8.3% (pea) and 13% (beans) were estimated to have outgrown the allergy by age 5, rising to 21%, 19.3%, 23.5% and 32.9% by age 15. [11] Foods that hide these legumes include hummus, falafel and pea protein in plant-based products.
Other beans (kidney, fava, green beans). We did not read a source with allergy numbers for these. Fava beans have a separate non-allergic risk for people with G6PD deficiency: see favism and G6PD deficiency.
Labels and eating out
| Place | Rule |
|---|---|
| United States | Nine major allergens must be named on the label at least once, either in parentheses after the ingredient or in a "contains" statement. These include peanuts and soybeans, and sesame since January 1, 2023. "May contain" statements are voluntary. [1] Lupin is not a major allergen, but lupin and its ingredients must be named in the ingredient list. [2] |
| European Union | Lupin is one of 14 allergens to declare on pre-packaged foods, including non-packaged foods in restaurants and shops. [3] |
| United Kingdom | Lupin is one of the 14 major allergens and is highlighted on ingredient labels. [4] |
| Australia and New Zealand | Allergen labeling for lupin is mandatory. Look for lupin flour, lupin flakes, lupinus, lupine, lupini or lupine beans. [5] |
| Canada | Chua and Chan say only peanut and soy are required to be declared, while lupin is a priority allergen in the EU and Australia. [8] |
Rules differ by country, and the 2022 review notes that mismatched rules can lead to accidental exposure. [8] Read labels every time, and ask restaurants about lupin, pea protein and soy flour. Recipes change.
What to do if you suspect a legume allergy
- Stop eating the food and talk to your doctor. Do not test at home with a large portion. In the Chua and Chan review, the median eliciting dose for 5% of allergic people was 15.3 mg of protein for lupin and 10.1 mg for soy, which is a very small amount. [8]
- An allergist can use history, skin prick or blood tests, and supervised food challenges. Tests alone do not predict how severe a reaction will be. [3] The Dutch authors say blinded food challenges are needed to confirm or exclude co-allergy. [7]
- Report a lupin reaction in the US to the FDA's CAERS system. [2]
- Carry your emergency plan and medicines as prescribed. The AAAAI says to use self-injectable epinephrine right away for anaphylaxis, then call 911. [3] Anaphylaxis UK suggests carrying two in-date doses. [4]
- Asthma that is poorly controlled raises the risk of severe reactions, according to the AAAAI. [3]
Allergy is not intolerance. Gas from beans is a digestive effect, covered in beans, gas, FODMAPs and digestion. Lectin illness from raw kidney beans is a poisoning, not an allergy: see lectins in beans.
Related pages
Frequently asked questions
If I am allergic to peanuts, must I avoid all legumes?
Not automatically. In a Dutch study, peanut-allergic patients rarely had clinical allergy to other legumes (16.7% or less), although 70% were sensitized to lupine. [7] Ask your allergist which ones to test or avoid.
Is soy allergy related to peanut allergy?
They can occur together: 63.3% of soy-allergic Dutch patients were also allergic to peanut. [7] The Chua and Chan review says soy sensitization correlates poorly with clinical reaction to peanut. [8]
Do I have to worry about lupin if I have a peanut allergy?
The FDA says people with peanut allergy face the highest risk of lupin reactions, and they can be severe. [2] Clinical reactivity ranged from about 4% to 37% depending on the study. [3] [6] Anaphylaxis UK says only a small number of people with peanut allergy are also allergic. [4]
Can children outgrow chickpea or lentil allergy?
Some do. In a London study, estimated resolution by age 15 was 21% for lentil and 19.3% for chickpea, and children with lower test results were more likely to outgrow it. [11]
What should I do in a severe reaction?
Use prescribed epinephrine right away, then call 911 or your local emergency number. [3] Without it, call emergency services immediately.
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Children and pregnancy
References
- U.S. Food and Drug Administration. Food allergies. Read 2026-10-24.
- U.S. Food and Drug Administration. Consumer advice on lupin. Current as of January 4, 2018. Read 2026-10-24.
- American Academy of Allergy, Asthma and Immunology. Lupin allergy. Page dated May 12, 2026. Read 2026-10-24.
- Anaphylaxis UK. What is lupin allergy?. No date shown. Read 2026-10-24.
- Australasian Society of Clinical Immunology and Allergy (ASCIA). Lupin allergy. Patient FAQ, April 2024. Read 2026-10-24.
- Soller L, La Vieille S, Chan ES. First reported case in Canada of anaphylaxis to lupine in a child with peanut allergy. Allergy Asthma Clin Immunol 2018;14:64. Case report; no funding, some authors disclosed industry ties. Read 2026-10-24.
- Smits M, Verhoeckx K, Knulst A, et al. Co-sensitization between legumes is frequently seen, but variable and not always clinically relevant. Front Allergy 2023;4. Funded by the Academy of Finland. Read 2026-10-24.
- Chua GT, Chan ES. A practical focus on legume oral immunotherapy. J Food Allergy 2022;4(2):144-147. Clinical review; no external funding, industry ties disclosed. Read 2026-10-24.
- Muller T, Luc A, Adam T, et al. Relevance of sensitization to legumes in peanut-allergic children. Pediatr Allergy Immunol 2022 (abstract read via Europe PMC). Read 2026-10-24.
- Chentouh MM, Codreanu-Morel F, Boutebba A, et al. Allergenic risk assessment of cowpea and its cross-reactivity with pea and peanut. Pediatr Allergy Immunol 2022 (abstract read via Europe PMC). In 27 legume-allergic children, cowpea extract strongly inhibited IgE binding to pea and peanut extracts. Read 2026-10-24.
- Atwah A, Swan K, Fox AT, Foong RX. The prevalence of outgrowing non-priority legume allergies in children. Pediatr Allergy Immunol 2025 (abstract read via Europe PMC). Read 2026-10-24.
- Mastrorilli C, Chiera F, Arasi S, et al. IgE-mediated legume allergy: a pediatric perspective. J Pers Med 2024 (abstract read via Europe PMC). Read 2026-10-24.
- Cosyns JCE, Frykas TLM, Hildebrand HV, et al. Peanut, soy, and emerging legume allergy in Canada. J Allergy Clin Immunol Glob 2022 (abstract read via Europe PMC). Read 2026-10-24.