Hazelnut allergy
Tree-nut allergy to hazelnuts; common in chocolate spreads.
About hazelnut allergy
Hazelnut is a tree nut and one of the more common nut allergies, familiar from chocolate spreads, pralines, cereals and baked goods. It is an IgE-mediated allergy in which the immune system produces antibodies to hazelnut proteins; on later exposure these trigger a rapid release of histamine and other chemicals. Reactions fall into two broad patterns. In birch-pollen areas, many people have a milder pollen-food cross-reaction to a birch-like hazelnut protein, while others are sensitised to more stable storage proteins that are linked to stronger, whole-body reactions.
Symptoms usually begin fast, often within minutes. The pollen-linked form tends to cause an itchy or tingling mouth and throat, especially with raw nuts, and roasting may reduce this. Sensitisation to storage proteins can cause hives, swelling, vomiting, wheeze and anaphylaxis, which can be life-threatening. Because tree nuts often share proteins and are processed together, people allergic to hazelnut may react to, or be advised to be cautious with, other tree nuts, and cross-contamination is a real concern.
Diagnosis combines your history with skin-prick or specific-IgE tests, and component testing can help tell the milder pollen pattern from the higher-risk one. Management is avoidance, careful label-reading and awareness of "may contain nuts" warnings. Anyone at risk of anaphylaxis should carry an adrenaline auto-injector and know how to use it. A severe reaction is a medical emergency: use the injector and call 999 immediately.
Common triggers
- Hazelnuts and praline\nChocolate spreads\nBaked 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.