Tree Nut Allergy
Also known as: Nut allergy
Tree nut allergy covers a broad group of nuts — almonds, cashews, walnuts, pistachios, hazelnuts and others. Reactions range from mild oral tingling to severe anaphylaxis, and allergies to multiple tree nuts are common.
Category
Food Allergies
Severity
Can be Life-ThreateningPrevalence
Affects about 1% of the population; second only to peanut as a cause of fatal food anaphylaxis.
Emergency Information
Use adrenaline auto-injector at the first sign of throat tightening, severe breathing difficulty, or collapse. Call emergency services immediately.
Symptoms
Airways & Breathing
- Throat tightening
- Wheezing
- Difficulty swallowing
Skin
- Hives
- Facial or lip swelling
- Eczema flare
Digestive
- Nausea
- Vomiting
- Abdominal pain
Systemic / Other
- Anaphylaxis
- Dizziness
- Loss of consciousness
How It's Diagnosed
- Skin prick testing to individual nut extracts (cashew, almond, walnut, hazelnut, pistachio)
- Specific IgE blood tests per nut — useful to identify which nuts are safe
- Component-resolved testing (e.g. Ana o 3 for cashew, Cor a 9/14 for hazelnut)
- Supervised oral food challenge when tests are equivocal
Avoidance Strategies
- Identify which specific nuts you react to — you may tolerate some tree nuts
- Check labels for each nut by name; 'tree nuts' on labels may cover many species
- Marzipan, nougat, pesto, and Nutella often contain nuts without obvious labelling
- Nut oils (expressed) may retain allergenic proteins
- Inform restaurants — Asian, Middle Eastern, and pastry cuisines use nuts extensively
- Carry prescribed adrenaline auto-injector
Cross-Reactivity
- Cashew and pistachio are botanically related and often co-allergenic
- Almond and peach share PR-10 proteins — relevant in birch-pollen sensitised individuals
- Peanut shares processing environments but is not a tree nut
Which nuts are tree nuts?
- Almonds, cashews, walnuts, pecans, pistachios, hazelnuts, Brazil nuts
- Macadamia, pine nuts, chestnuts, coconut (botanically a fruit but classified as a tree nut allergen)
- Peanuts are NOT tree nuts — they are legumes that grow underground
Are you allergic to all tree nuts?
Not necessarily. Some individuals react to all tree nuts; others to only one or two. Specific IgE testing and, where appropriate, supervised food challenges can help identify which nuts are actually causing your immune response.
Never self-challenge at home — an allergist should guide the process, particularly for high-risk individuals.
Related Allergens
Medical disclaimer
This page is for educational purposes only. Allergy diagnosis and management must be carried out by a qualified allergist. Do not attempt to test yourself with suspected allergens. Always carry prescribed emergency medications and follow your written action plan.
Reviewed 2026-06-01 · Looms Medical Team