Paeds · allergy-and-immunology
Peanut, tree-nut and seed allergy
Also known as Peanut allergy · Tree-nut allergy · Seed allergy · Nut allergy · Sesame allergy · Cashew allergy
Fellowship guide to peanut, tree-nut and seed allergy in children: IgE-mediated pathophysiology and storage-protein families, the HealthNuts natural-history data, diagnosis with skin-prick testing, specific IgE and component-resolved diagnostics, anaphylaxis recognition and adrenaline dosing, the LEAP trial and primary prevention through early introduction, oral immunotherapy, and the practicalities of avoidance, action plans and autoinjectors across ANZ and international practice.
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Target exams
Red flags
- Rapid onset of multi-system reaction within minutes of nut or seed exposure — anaphylaxis until proven otherwise
- Stridor, wheeze, persistent vomiting, pallor or hypotension after ingestion — give IM adrenaline immediately
- A child who is frightened, quiet, or reports a sense of impending doom alongside flushing — early anaphylaxis, do not wait
- Biphasic recurrence of symptoms 4 to 24 hours after an apparently resolved reaction
- First reaction at adolescence with a large allergen dose and exercise or NSAID cofactor — high risk of severe anaphylaxis
- Asthma as a comorbidity markedly increases the risk of fatal food-induced anaphylaxis
- Cashew and walnut allergy in young children — storage-protein driven and often severe from small exposures
Life stages
Care settings
Clinical exam formats
Board mappings
- Distinguishes IgE-mediated nut allergy from oral allergy syndrome and intolerance
- Recognises anaphylaxis and gives intramuscular adrenaline at the correct dose and site
- Initiates age-appropriate peanut introduction for allergy prevention
- Interprets skin-prick testing, specific IgE and component-resolved diagnostics (Ara h 2, Ana o 3)
- Counsels on cross-reactivity between peanut, tree nuts and seeds and when supervised oral food challenge is indicated
- Discusses oral immunotherapy indications, benefits and risks with a family
- Assessment and initial management of a child with suspected nut or seed anaphylaxis
- Counselling a family after a first allergic reaction, including an action plan and adrenaline autoinjector
- Approach to a high-risk infant for peanut introduction and prevention
- Long-case discussion of a child with multiple food allergies, asthma and growth concerns
- Communication of a new diagnosis and shared decision-making about avoidance and immunotherapy
- Level 1: Recognises food allergy and anaphylaxis
- Level 2: Initiates investigations, action plans and prevention advice
- Level 3: Manages complex allergy, component diagnostics and immunotherapy referral
- Pathophysiology of IgE-mediated food allergy and the storage-protein allergen families
- LEAP trial evidence and primary-prevention feeding guidance
- Diagnosis with skin-prick testing, specific IgE and oral food challenge
- History and examination of a child with suspected nut allergy
- Communication of management plan, autoinjector training and school advice
- Structured assessment of a child presenting with anaphylaxis
- Recognition and management of food-induced anaphylaxis
- Appropriate use of diagnostic testing and avoidance of overdiagnosis
- Infant feeding guidance for food allergy prevention
- Recognition and resuscitation of the child with anaphylaxis
- Evidence-based prevention through early introduction of allergenic foods
- Coordination with allergy specialists for complex or persistent disease
- Canadian approach to peanut and tree-nut allergy diagnosis and prevention
- Anaphylaxis management and school autoinjector policy
- Referral pathways for oral immunotherapy and component diagnostics
Overview & Definition
Peanut, tree-nut and seed allergy together form the group of food allergies most likely to persist for life and to cause severe or fatal reactions in children. A child who reacts to a trace of peanut within minutes of eating it, with urticaria spreading across the face and a tightening throat, sits at the severe end of a spectrum that also includes the toddler with only lip swelling from cashew paste and the school-age child whose only problem is itchy mouth after a hazelnut cross-reacting with birch pollen. The clinician's job is to separate the dangerous, persistent, storage-protein-driven allergies from the milder cross-reactive and the non-IgE-mediated forms, and to do so without over-labelling children who are only sensitised. [8]
Peanut is a legume, not a nut, and its cross-reactivity with tree nuts is driven less by botanical kinship than by shared stable storage proteins that resist digestion and cooking. Tree nuts include walnut, cashew, hazelnut, almond, pecan, pistachio, Brazil nut and macadamia, while the major seed allergens are sesame, sunflower, poppy and mustard. Each carries distinctive allergen components — Ara h 2 in peanut, Ana o 3 in cashew, Ses i 1 in sesame — and knowing which components matter transforms a vague positive test into a meaningful clinical prediction. [9]
The single most important advance in this field is preventive. The LEAP trial showed that early, sustained consumption of peanut in high-risk infants reduced the later development of peanut allergy by roughly 80 per cent compared with avoidance, overturning decades of advice to delay allergenic foods. Alongside prevention, modern management pairs strict avoidance and adrenaline autoinjectors with the emerging option of oral immunotherapy, which desensitises rather than cures and must be weighed against its real risk of allergic reactions during treatment. [1]
References15ShowHide
- [1]Du Toit G, Roberts G, Sayre PH, et al. Randomized trial of peanut consumption in infants at risk for peanut allergy. N Engl J Med, 2015.PMID 25705822
- [2]Perkin MR, Logan K, Tseng A, et al. Randomized Trial of Introduction of Allergenic Foods in Breast-Fed Infants. N Engl J Med, 2016.PMID 26943128
- [3]Peters RL, Allen KJ, Dharmage SC, et al. Natural history of peanut allergy and predictors of resolution in the first 4 years of life: a population-based assessment. J Allergy Clin Immunol, 2015.PMID 25725989
- [4]Peters RL, Guarnieri I, Tang MLK, et al. The natural history of peanut and egg allergy in children up to age 6 years in the HealthNuts population-based longitudinal study. J Allergy Clin Immunol, 2022.PMID 35597613
- [5]Sicherer SH, Muñoz-Furlong A, Godbold JH, Sampson HA US prevalence of self-reported peanut, tree nut, and sesame allergy: 11-year follow-up. J Allergy Clin Immunol, 2010.PMID 20462634
- [6]Vickery BP, Vereda A, Casale TB, et al. AR101 Oral Immunotherapy for Peanut Allergy. N Engl J Med, 2018.PMID 30449234
- [7]Jones SM, Kim EH, Nadeau KC, et al. Efficacy and safety of oral immunotherapy in children aged 1-3 years with peanut allergy (IMPACT trial). Lancet, 2022.PMID 35065784
- [8]Boyce JA, Assa'ad A, Burks AW, et al. Guidelines for the diagnosis and management of food allergy in the United States: report of the NIAID-sponsored expert panel. J Allergy Clin Immunol, 2010.PMID 21134576
- [9]Stiefel G, Anagnostou K, Boyle RJ, et al. BSACI guideline for the diagnosis and management of peanut and tree nut allergy. Clin Exp Allergy, 2017.PMID 28836701
- [10]McWilliam V, Peters R, Tang MLK, et al. Patterns of tree nut sensitization and allergy in the first 6 years of life in a population-based cohort. J Allergy Clin Immunol, 2019.PMID 30171872
- [11]Brettig T, Soriano VX, Dharmage SC, et al. Cashew Allergy Prevalence and Sensitization in 1-Year-Old Infants. J Allergy Clin Immunol Pract, 2023.PMID 37481112
- [12]Shaker MS, Wallace DV, Golden DBK, Oppenheimer J, Bernstein JA, Campbell RL, et al. Anaphylaxis — a 2020 practice parameter update, systematic review, and Grading of Recommendations, Assessment, Development and Evaluation (GRADE). J Allergy Clin Immunol, 2020.PMID 32001253
- [13]Muraro A, Worm M, Alviani C, et al. EAACI guidelines: Anaphylaxis (2021 update). Allergy, 2022.PMID 34343358
- [14]Santos AF, Riggioni C, Agache I, et al. EAACI guidelines on the diagnosis of IgE-mediated food allergy. Allergy, 2023.PMID 37815205
- [15]Santos AF, Riggioni C, Agache I, et al. EAACI guidelines on the management of IgE-mediated food allergy. Allergy, 2025.PMID 39473345