The First Steps With Food Allergy
Food Allergy: the few things that matter most, and the mistakes that catch people out early.
An immune reaction to a food protein, ranging from mild to life-threatening.
Key takeaways
- Mechanism: usually IgE-mediated, causing rapid reactions
- Common triggers: milk, egg, peanut, tree nuts, fish, shellfish, soya, wheat, sesame
- Most useful single change: Get a proper diagnosis before excluding foods long term.
- Commonest mistake: Commercial IgG or hair-analysis tests.
- See a doctor if any of the signs under "When to speak to a doctor" below apply to you.
Why bother
It is fundamentally different from intolerance, and the tests sold for intolerance do not diagnose either.
Start here
Two things, and nothing else until both feel routine.
- Get a proper diagnosis before excluding foods long term
- Read labels every time; recipes change without warning
Then add these
When those have settled in, these are worth adding.
- Tell restaurants clearly and ask about cross-contamination
- Carry prescribed adrenaline auto-injectors at all times
The numbers, in one place
| Measure | Figure |
|---|---|
| Mechanism | usually IgE-mediated, causing rapid reactions |
| Common triggers | milk, egg, peanut, tree nuts, fish, shellfish, soya, wheat, sesame |
| Diagnosis | clinical history plus skin prick or specific IgE testing |
| IgG food tests | not recommended; they do not diagnose allergy |
| Labelling | 14 major allergens must be emphasised in ingredients lists |
Common early mistakes
- Commercial IgG or hair-analysis tests
- Excluding major food groups without dietetic support
- Assuming "may contain" is safe
Where to go next
- Food Allergy: Just the Figures
- Food Allergy: What the Evidence Actually Says
- Food Allergy — the reference entry
- What the Guidance Really Says About Hay Fever and Pollen
- Allergy Testing: What Published Guidance Supports
When to speak to a doctor
Call 999 for swelling of the lips, tongue or throat, difficulty breathing or swallowing, a hoarse voice, or collapse after eating — use an adrenaline auto-injector immediately if prescribed. See a GP for referral to an allergy service rather than self-diagnosing, and never reintroduce a suspected allergen at home without medical supervision.
Where this comes from
- NICE — Food allergy in under 19s
- Food Standards Agency — allergen guidance
How this page was put together
Every figure, recommendation and warning above is taken from the guidance named in Where this comes from. Nothing on this page is inferred, summarised or generalised beyond what those bodies publish: where they give a number, it is their number, and where they are silent, so are we. Pages are rebuilt whenever the underlying record changes. Sign-off by a named clinician, where it has happened, is shown at the top of the page along with the date.
Medical disclaimer
This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to a GP, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 999.
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