NICE vs BSACI: Management of Food Allergy in Adults (2025)
In the UK, clinicians managing adult food allergy primarily refer to two key evidence-based guidelines: the National Institute for Health and Care Excellence (NG221) and the British Society for Allergy & Clinical Immunology (BSACI). While complementary, they serve distinct purposes. NICE provides a standardised, national framework for the NHS, emphasising diagnostic pathways and service organisation. BSACI, as a specialist society, offers more detailed, nuanced guidance on complex clinical scenarios and emerging treatments. This comparison highlights their respective strengths and key differences to aid clinicians in applying them effectively in practice.
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Diagnosis and Assessment
NICE (NG221)
NICE provides a highly structured, stepwise diagnostic algorithm focused on preventing over-investigation. It is designed for use in both primary and secondary care.
- History First: Emphasises a detailed clinical history as the cornerstone. Recommends using a structured allergy-focused history.
- Selective IgE Testing: Strongly advises against blanket panel testing for food-specific IgE (sIgE). Testing should be guided by history, targeting one or a few specific suspected allergens.
- Definitive Role of Oral Food Challenge (OFC): Positions OFC as the gold standard for diagnosis, particularly when history and test results are discordant or for assessing resolution.
- Component-Resolved Diagnostics (CRD): Acknowledges CRD but offers cautious guidance, suggesting it may be considered by specialists to distinguish between primary allergy and pollen-food syndrome (PFS) for certain allergens like peanut.
BSACI
BSACI's guidance is more detailed on the interpretation of tests and is written from a specialist secondary/tertiary care perspective.
- In-Depth Test Interpretation: Provides comprehensive guidance on sIgE levels, skin prick test (SPT) wheal sizes, and their predictive values, acknowledging their variability between centres.
- Proactive Use of CRD: Actively encourages the use of CRD in specific scenarios (e.g., peanut, hazelnut, egg) to refine risk assessment by differentiating between sensitisation to labile (e.g., Ara h 8, associated with PFS) and stable (e.g., Ara h 2, associated with systemic allergy) proteins.
- OFC Indications: Similarly champions OFC but provides more extensive detail on its practical conduct, indications, and safety protocols.
Key Difference & Practical Takeaway
NICE provides the essential gatekeeping pathway to avoid inappropriate testing in primary care. BSACI gives the specialist the detailed toolkit to interpret complex results. In practice, follow the NICE algorithm for initial assessment and refer to BSACI for complex cases requiring nuanced test interpretation, especially where CRD can clarify risk.
Treatment and Ongoing Management
NICE (NG221)
NICE focuses on core management principles, safety netting, and patient education.
- Avoidance and Adrenaline: Cornerstones are strict allergen avoidance and provision of adrenaline auto-injectors (AAIs) for those at risk of anaphylaxis.
- Patient Education: Mandates structured education on label reading, managing cross-contamination, and recognising/treating allergic reactions.
- Nutritional Support: Strong recommendation for access to a dietitian with expertise in food allergy.
- Oral Immunotherapy (OIT): States that OIT should not be used for managing food allergy in adults except within the context of a research study. This is a significant point of divergence.
BSACI
BSACI covers the same core principles but also addresses advanced and emerging therapies.
- Comprehensive Management Plans: Provides templates and detailed advice for creating personalised allergy action plans.
- Position on OIT: Acknowledges OIT as an emerging, specialist-driven treatment. While not recommending it for routine NHS use, it outlines the evidence, patient selection criteria, and protocols for specialists conducting OIT within controlled clinical settings. This reflects an evolving landscape.
- Biologics: Discusses the potential role of biologics like omalizumab as adjuncts to OIT or for difficult-to-manage cases.
Key Difference & Practical Takeaway
The most striking difference is the stance on Oral Immunotherapy. NICE is definitive: OIT is not for routine care. BSACI is descriptive: OIT is a specialist option with specific criteria. For most NHS clinicians, the NICE position is the current standard. BSACI guidance is essential for clinicians working in or referring to specialist centres exploring OIT.
Special Situations
Pollen-Food Syndrome (PFS)
NICE clearly outlines the typical history (oral symptoms with raw fruit/veg in a pollen-allergic individual) and advises that diagnosis is often clinical, avoiding unnecessary sIgE testing. BSACI offers a deeper dive, detailing the specific pollen-plant-food cross-reactivities and actively promoting the use of CRD (e.g., Bet v 1 vs Bet v 2 for birch pollen related allergies) to confirm the diagnosis in uncertain cases.
Food-Dependent Exercise-Induced Anaphylaxis (FDEIA)
Both guidelines recognise this entity. NICE mentions it within the history-taking process. BSACI provides more comprehensive guidance on investigation, which often requires specialist tests like exercise challenge testing combined with food provocation.
Key Takeaway
For common issues like PFS, NICE provides a robust framework for first-line diagnosis. For complex or rare conditions like FDEIA, BSACI serves as the essential reference for specialist investigation and management.
Practical Clinical Flow for UK Clinicians
- Primary Care / Initial Assessment: Follow the NICE algorithm. Take a detailed allergy-focused history. Avoid panel testing. Order sIgE tests only for specific suspected allergens from the history.
- Referral to Secondary Care: Refer if diagnosis is uncertain, if there is a history of anaphylaxis, or for multiple food allergies. Use NICE criteria to guide referral.
- Secondary Care / Specialist Management: Use BSACI guidance for in-depth test interpretation (SPT, sIgE, CRD), conducting OFCs, and creating detailed management plans.
- Complex Cases / Tertiary Referral: For consideration of OIT or complex presentations (e.g., FDEIA), BSACI is the primary resource. These patients should be managed in specialist centres.
- Ongoing Care & Education: Both guidelines emphasise patient education and dietetic input. NICE provides the strong recommendation for this as a standard of care.
Frequently Asked Questions (FAQs)
1. Which guideline should I use as a GP?
Primarily NICE (NG221). It is designed for you. Its clear diagnostic pathway prevents unnecessary testing and ensures appropriate referral. Refer to BSACI for understanding what happens after you refer a patient or for deeper insight into test interpretation.
2. A patient asks about peanut oral immunotherapy (OIT). What is the NHS position?
Based on the current NICE guideline, OIT is not recommended for routine NHS management of food allergy. It should only be offered within the context of a research study. You should explain that while it is an area of active research, it is not a standard treatment due to uncertainties about long-term efficacy and safety.
3. When should I consider using Component-Resolved Diagnostics (CRD)?
In primary care, routinely? Never. In secondary care, consider it when the diagnosis is unclear, particularly to differentiate between a primary peanut allergy (risk of anaphylaxis) and Pollen-Food Syndrome (mild, oral symptoms) in a patient sensitised to birch pollen. BSACI provides detailed guidance on this specific indication.
4. How should I manage an adult with suspected pollen-food syndrome?
As per NICE, take a clear history focusing on symptoms with raw fruits/vegetables and a background of hay fever. Diagnosis is often clinical. Avoid sIgE testing to the foods; if testing is done, it should be guided by history. Management is reassurance and advising avoidance of raw triggers (cooked forms are often tolerated).
5. Are the guidelines for adults different from those for children?
Yes. Both NICE and BSACI have separate guidelines for children. The guidelines discussed here (NICE NG221 and the BSACI adult guideline) are specific to adults. Key differences in adults include the focus on pollen-food syndrome, persistence of allergies like peanut and tree nut, and the presentation of new-onset allergies being less common and requiring careful evaluation.
Source Links
- NICE Guideline NG221 (2024): Food allergy in adults and young people: diagnosis and assessment. [https://www.nice.org.uk/guidance/ng221]
- NICE Guideline NG221 (2024): Food allergy in adults and young people: management. [https://www.nice.org.uk/guidance/ng221] (Note: Diagnosis and management are covered in a single NICE guideline).
- BSACI Guideline (2022): Skypala, I. J. et al. BSACI guideline for the diagnosis and management of peanut and tree nut allergy. Clin Exp Allergy. 2022; 52: 7–31. [https://doi.org/10.1111/cea.14055] (Note: BSACI guidelines are often allergen-specific; this is a key example).
- BSACI Guideline (2019): Patel, N. et al. BSACI guideline for the diagnosis and management of non-allergic food hypersensitivity. Clin Exp Allergy. 2019; 49: 728–739. [https://doi.org/10.1111/cea.13385] (Covers conditions like Pollen-Food Syndrome).