Nut allergy is an immune reaction to peanuts, tree nuts or both. Peanuts are legumes, while tree nuts include foods such as almonds, cashews, hazelnuts, pistachios and walnuts. A person may be allergic to one nut and tolerate others, but this should be assessed individually.
Symptoms
- Itching or tingling in the mouth
- Hives, redness or swelling
- Abdominal pain, vomiting or diarrhea
- Coughing, wheezing, breathlessness or a hoarse voice
- Dizziness or fainting
When to get emergency help
Contact your local emergency services immediately for swelling of the tongue or throat, breathing difficulty, collapse, severe dizziness or loss of consciousness. Use a prescribed epinephrine auto-injector immediately according to the person’s emergency plan and device instructions.
Diagnosis
Assessment includes the details and timing of previous reactions. Skin prick tests, specific IgE blood tests or a supervised food challenge may be used. A positive test alone does not always prove clinical allergy, so results must be interpreted together with the medical history.
Living safely with nut allergy
Avoid confirmed allergens, check food labels and tell restaurants, schools and caregivers about the allergy. Follow professional advice about precautionary allergen labels and cross-contact. People prescribed epinephrine auto-injectors should keep them available and know how to use them.
Do not test a suspected nut allergy at home. Parents should seek professional advice before excluding several nuts from a child’s diet or introducing nuts when a child has a known food allergy or severe eczema.
Related topics
Sources and Further Reading
Last reviewed: 4 September 2026. This page provides general health information and does not replace individual medical assessment or treatment.