Concierge allergy diagnostics · London
Supervised food challenge, the gold-standard test for confirming or excluding food allergy.
A supervised graded food challenge in an allergy day-unit is the gold-standard for confirming or excluding food allergy. Common foods: peanut, tree nuts, milk, egg, wheat, sesame. Performed only where full resuscitation is available.
Why patients choose us
- 01
The right hands
We route you to a consultant allergist working in a fully-equipped day-unit — the only safe setting for a supervised food challenge.
- 02
Definitive by design
A supervised graded food challenge is the gold-standard — it gives you a yes-or-no answer that skin-prick and blood tests can’t.
- 03
Independent, and free
We are paid by no clinic, so the recommendation is impartial and costs you nothing.
Key facts
The six things to know about a food challenge.
What it is, why it’s the gold-standard, where it can safely be done, and what you leave with.
In short
A supervised graded food challenge is the gold-standard for confirming or excluding food allergy — day-unit only.
-
What it is
A supervised graded oral food challenge performed in an allergy day-unit.
-
Why it matters
The gold-standard test for confirming or excluding an IgE-mediated food allergy.
-
Where it is done
In an allergy day-unit with full resuscitation equipment and consultant cover.
-
What comes first
Skin-prick testing and specific IgE bloods — the challenge only runs after those.
-
Risk stratification
Component-resolved diagnostics (e.g. Ara h 2 for peanut) guide who is safe to challenge.
-
What you leave with
Definitive tolerance data or a clear reaction pattern — plus a written management plan.
The problem
A skin-prick or blood test alone can’t tell you if you’re allergic.
Sensitisation is not the same as allergy — many people test positive but tolerate the food. Only a supervised challenge gives a definitive answer.
-
Positive blood test, uncertain history?
We assess whether a supervised challenge will safely settle the question.
-
Outgrown a childhood allergy?
A challenge confirms tolerance and gets the food back on the plate.
-
Reaction with exercise, not at rest?
A food-plus-exercise challenge identifies FDEIA and its trigger dose.
Preparation
From consultation to report — what happens, in order.
One consultant allergist from first consultation to signed tolerance report — usually over two or three visits.
Phase 1 · Before the challenge
Consultation, workup and medication changes
Phase 2 · On the day
A full day in the allergy day-unit
Phase 3 · After
Signed report and management plan
- 01
Before
Consultant allergist consultation
A detailed history, review of prior skin-prick and specific IgE results, and a decision on whether a challenge is the right next step.
- 02
Before
Withhold antihistamines 5–7 days
Antihistamines mask reactions and must be stopped in advance. We give you a written stop-medication list.
- 03
Before
Baseline observations
On arrival: pulse, blood pressure, oxygen saturations, peak flow and a skin check to set your baseline.
- 04
On the day
Graded oral doses at 15–30 min
Incremental doses of the food are given at set intervals, starting well below the expected reaction threshold.
- 05
On the day
Continuous observation for reaction
A nurse and consultant observe throughout — skin, respiratory, cardiovascular and gastrointestinal signs at every step.
- 06
On the day
Rescue treatments ready
Adrenaline, antihistamines, steroids, oxygen and IV access are drawn up and immediately available for every challenge.
- 07
After
Written report and clear tolerance
A consultant-signed report with a clear tolerance statement — the exact dose passed, or the reaction pattern seen.
Typical pathway: consultation, then a full challenge day within 2–4 weeks.
What it shows
What a supervised food challenge can definitively tell you.
A food challenge answers one clean question: does this food, at a real-world dose, cause a reproducible reaction — and if so, at what threshold.
-
Confirmed food allergy
A reproducible reaction at a defined dose — the diagnosis is now certain, not presumed.
-
Confirmed tolerance
A full portion taken without reaction — the food can safely be reintroduced to the diet.
-
IgE-mediated reaction pattern
Immediate urticaria, angio-oedema or wheeze — classic type-1 hypersensitivity, minutes after a dose.
-
Non-IgE food allergy
Delayed gastrointestinal or eczematous reactions — a different mechanism, requiring a different plan.
-
Oral allergy syndrome
Local oropharyngeal itch or tingling from cross-reactive plant proteins — usually mild and food-specific.
-
Food-dependent exercise-induced anaphylaxis
Reaction only when the food is combined with exercise — identified by a specific challenge protocol.
-
Threshold dose established
The exact amount that triggered symptoms — critical for labelling advice and school or workplace plans.
-
Red flag: anaphylaxis during challenge — halt and treat per BSACI protocol
Immediate IM adrenaline, airway support and observation. The challenge is halted; a written plan follows.
Next steps
What follows a challenge — whichever way it goes.
A challenge is only useful if it changes what you do next. Every result comes with a concrete, personalised plan.
-
Update allergy record
Your NHS and private allergy record is updated with the definitive tolerance or reaction data.
-
Adrenaline auto-injector prescription
Two in-date auto-injectors prescribed where indicated, with a demonstration and trainer pen.
-
Antihistamine / steroid plan
A tiered written plan for mild, moderate and severe reactions — drug, dose and timing.
-
Alternative food substitution
Practical, nutritionally-matched substitutes for the food being avoided.
-
Oral immunotherapy referral
Referral into a peanut, milk or egg desensitisation programme where you are a suitable candidate.
-
Written management plan
A BSACI-format personalised action plan for you, your GP and — where relevant — your school or employer.
-
Dietician referral
A specialist allergy dietician to protect nutrition, especially in children and multi-food avoidance.
-
Structured allergist follow-up
Scheduled review to reassess sensitisation, repeat the challenge, or step down the plan over time.
Our vetted London network
A small panel of allergy day-units, we picked them.
Consultant allergists with dedicated challenge lists in fully-equipped day-units. Introductions are made privately, once we understand your case.
Selection criteria
How we choose every day-unit in our network.
-
Consultant allergists with a dedicated day-unit challenge list
-
Full resuscitation equipment, drawn-up adrenaline and immediate consultant cover
-
BSACI-format written management plan and a signed tolerance statement
-
Onward oral immunotherapy or dietician pathway if the challenge confirms allergy
Safety and red flags
When to defer, when to press ahead, and when it’s a 999 call.
A supervised challenge in a day-unit is safe — but the checklist below decides whether today is the right day, and what would tip a reaction into an emergency.
-
Only in a day-unit
A supervised food challenge is never done at home or in a standard outpatient room — it needs full resuscitation on hand.
-
Antihistamines must be stopped
Stop non-sedating antihistamines 5–7 days before the challenge; sedating antihistamines 3 days before.
-
Well on the day
Any acute illness, wheeze or fever in the 48 hours before means the challenge is postponed, not pushed through.
-
Asthma must be controlled
Poorly controlled asthma is the single biggest risk factor for a severe reaction — inhalers reviewed first.
-
Beta-blockers reviewed
Beta-blockers blunt the response to adrenaline. Where possible they are switched or held before the challenge.
-
Anaphylaxis is a 999 call
Any reaction outside the day-unit — biphasic, delayed or at home — is a 999 call, not a wait-and-see.
-
A negative challenge is not lifelong
Tolerance can be re-lost, particularly with peanut and tree nuts — periodic re-challenge may be advised.
-
Pregnancy is a relative contra
Elective food challenges are generally deferred in pregnancy unless the risk-benefit clearly favours proceeding.
-
Bring your prior allergy results
Skin-prick sizes, specific IgE and component results materially change the challenge protocol and dose steps.
Reading your report
A challenge report is short by design. It has to be clear.
Whatever the outcome, the report keeps to the same four parts.
A quiet reminder
The report is written for your GP and school — and for you, in plain English.
If you would like us to talk you through it before your follow-up, just ask.
- 01 Header
Indication and prior allergy results
Your details, the food being challenged, and the skin-prick / specific IgE / component results that led to the challenge.
- 02 Protocol
Dose steps and observation intervals
The exact dosing ladder used, the timing of observations, and the medications drawn up on standby.
- 03 Findings
Symptoms, dose reached, threshold
A step-by-step account: symptoms at each dose, the dose that triggered a reaction, and the treatment given.
- 04 Impression
Tolerance or reaction — read this first
The definitive statement — tolerant, reactive, or inconclusive — and the concrete next step for you and your GP.
Recognised by major UK insurers
Cover depends on your policy and clinic; we confirm with your insurer before booking.
Frequently asked
Everything we get asked about food challenges.
Quick answers on what a challenge is, which foods, why blood tests aren’t enough, and what happens if you react.
-
What is a supervised food challenge?
It is the gold-standard test for food allergy: a consultant allergist gives you graded oral doses of the food at 15–30 minute intervals in a day-unit, watching for any reaction. It gives you a definitive yes-or-no answer that skin-prick and blood tests alone can’t.
-
Which foods are commonly challenged?
The most common are peanut, tree nuts (cashew, walnut, almond, hazelnut), cow’s milk, egg, wheat and sesame. Fish, shellfish and soya challenges are also performed where clinically indicated.
-
Why not just rely on skin-prick or blood tests?
Skin-prick and specific IgE tests measure sensitisation, not allergy — many people test positive but tolerate the food. A supervised challenge is the only way to prove clinical reactivity or true tolerance.
-
How long does a food challenge take?
Plan for a full day at the unit. The dosing ladder itself takes 2–4 hours, followed by a 2-hour observation period after the final dose before you go home.
-
Is it safe to do a food challenge?
Yes, when done in the right setting. It is performed only in an allergy day-unit with full resuscitation equipment, immediate consultant cover and drawn-up adrenaline. Reactions are managed per the BSACI anaphylaxis protocol.
-
What happens if I react during the challenge?
The challenge is halted and you are treated immediately — typically IM adrenaline for anaphylaxis, plus antihistamines, steroids and observation. You leave with a written plan and, where indicated, an adrenaline auto-injector.
Sources
Guidelines this page is written from.
- British Society for Allergy and Clinical Immunology (BSACI). Food challenge and anaphylaxis guidelines.
- NICE. Anaphylaxis: assessment and referral after emergency treatment (CG134).
- EAACI. Guidelines on the diagnosis and management of food allergy.
- Royal College of Paediatrics and Child Health. Allergy care pathways.
Last reviewed 2026-07-30 · Next review 2027-07-30 · Reviewed by Pulse Atlas Editorial Board,
Related tests
Looking for a different test?
-
Drug provocation testing
Supervised graded drug challenge — the gold-standard for confirming or excluding drug allergy.
Learn more -
Allergy tests
Skin-prick, patch and specific IgE testing — the first-line allergy workup.
Learn more -
Allergy blood tests
Specific IgE and component-resolved diagnostics for food and inhalant allergens.
Learn more -
All tests
Browse every test and procedure we arrange.
Learn more -
Hypertension
Related condition guide.
Learn more -
Type 2 Diabetes
Related condition guide.
Learn more -
Cognitive Behaviour Therapy
Related treatment option.
Learn more -
Complementary Alternative Medicine
Related treatment option.
Learn more
In practice, in London
Getting food provocations challenges sorted in London, without the guesswork
With food provocations challenges, the London question is usually about report turnaround and the radiologist reading it — not whether the scan is available. On the NHS, food provocations challenges typically sits behind a triage step and a wait that can stretch from a few weeks into months. In London’s private sector, the same appointment often lands within days. That speed matters when symptoms are disrupting work, sleep, or a plan you’d already committed to — and it’s the single most common reason people call us in the first place.
In practice, a private food provocations challenges appointment in London means a named consultant, a proper hour in the room (or the equivalent on a video call), and a report you can actually read. Most of the imaging suites and endoscopy units we use sit within a mile of Harley Street or in Chelsea and Fulham, and turnaround on findings is measured in days, not weeks. For food provocations challenges specifically, the difference between a routine report and a sub-speciality read is where private care earns its keep.
The value of going through a concierge for food provocations challenges isn’t access — anyone with an insurer or a credit card can get a private appointment in London. The value is knowing which consultant reads this particular presentation best, which unit turns reports around fastest, and which pathway won’t hit a dead end if the findings point somewhere unexpected.
Nearby in the library