Lupin allergy
Lupin flour allergy; may cross-react with peanut.
About lupin allergy
Lupin comes from the seeds of the lupin plant, a legume related to peanuts, and lupin flour and seeds are used in some breads, pastries, pasta and gluten-free products, especially in parts of Europe. Lupin is a recognised food allergen that must be declared on labels in the UK and EU. It is IgE-mediated: the immune system produces antibodies to lupin proteins, and eating lupin triggers a release of histamine and other chemicals. People may become allergic to lupin directly, or react because of its close relationship to peanut.
Reactions typically begin quickly, within minutes, and can be severe, including anaphylaxis. Symptoms range from an itchy mouth, hives and swelling to vomiting, wheeze, throat tightness and collapse. A particularly important point is the recognised cross-reactivity with peanut: a notable proportion of people with peanut allergy may also react to lupin, so those with peanut allergy should be especially cautious with lupin-containing foods, though not everyone with peanut allergy will react.
Diagnosis is based on your history with skin-prick or specific-IgE testing, and sometimes a supervised food challenge. Management means avoiding lupin and reading labels carefully, as lupin flour can appear in bakery goods, gluten-free products and continental breads where it may not be obvious. Because it is a named allergen, packaged foods in the UK must declare it. Anyone at risk of anaphylaxis should carry an adrenaline auto-injector. A severe reaction is a medical emergency: use the injector and call 999.
Common triggers
- Lupin flour and seeds\nSome breads and baked goods
Symptoms
- Itching or tingling in the mouth
- Hives, itching or eczema
- Swelling of the lips, face, tongue or throat
- Stomach cramps, nausea, vomiting or diarrhoea
- Wheezing or trouble breathing
- In severe cases, anaphylaxis
Avoidance & management
- Read ingredient labels every time
- Ask about ingredients and cross-contamination when eating out
- Keep the food out of shared cooking areas
- Carry prescribed antihistamines or an adrenaline auto-injector
- Seek emergency help for any severe reaction
Sources & references
Allergy safety: what everyone should know
Mild-to-moderate reaction signs
- Itching, hives or a raised rash
- Swelling of lips, face or eyes
- Tingling mouth, sneezing, runny nose
- Stomach pain, nausea or vomiting
Anaphylaxis — call 999 (UK) or 112 (EU) immediately
- Difficult or noisy breathing, wheeze, persistent cough
- Swelling of the tongue or tightness in the throat
- Dizziness, collapse, pale and floppy (young children)
- Use an adrenaline auto-injector (e.g. EpiPen) at once if prescribed, then call an ambulance even if symptoms improve
Allergy or intolerance? A true allergy involves the immune system and can escalate quickly; an intolerance (e.g. lactose intolerance) is unpleasant but not life-threatening. The symptoms overlap, so self-diagnosis is unreliable.
Getting tested: home-testing kits based on IgG are not diagnostically valid. If you suspect an allergy, ask a GP for referral to an allergy clinic for skin-prick or specific-IgE testing and a supervised food challenge where appropriate.