Paediatric allergy · London
Paediatric allergy testing in London - the right test, at the right age, read by the right specialist.
A BSACI-registered paediatric allergist takes a detailed history and matches the workup to your child. Skin prick, specific IgE, component-resolved and, where needed, a hospital oral food challenge for definitive answers.
- BSACI-registered allergists
- GOSH, Evelina, Royal Brompton, St Mary's
- Reply within one working day
- Free
The assessment
History first, tests second.
The single most useful diagnostic tool is a careful clinical history. Tests confirm and stratify; they do not replace the conversation.
What the allergist asks
- Reaction timing, symptoms and severity
- Foods eaten in the four hours before onset
- The atopic march: eczema, asthma, allergic rhinitis
- Family history of atopy
- Feeding history and current diet, including exclusive breastfeeding and weaning
- Whether high-risk infants (severe eczema, egg allergy) had early peanut introduction at 4 to 6 months, per LEAP
What testing is for, and is not for
Use for
- Investigating a clinically suspected IgE-mediated allergy after a reaction
- Risk-stratifying accidental exposure and adrenaline autoinjector need
- Guiding reintroduction after outgrowing milk or egg (retest annually; consider OFC when IgE and SPT are dropping)
Do not use for
- Screening asymptomatic children (high false-positive rate)
- IgG food intolerance testing (not evidence-based)
- Routine broad panel testing without a clinical question
The tests
Six tools, chosen to fit the question.
Positive tests without a matching history mean sensitisation, not allergy. The allergist decides which of the six is right for your child.
- 01
Skin prick test (SPT)
Gold standard for IgE-mediated allergy from age 6 months. A drop of allergen on the forearm, a tiny lancet, a wheal read at 15 minutes. Positive when the wheal is 3 mm or more above the negative control. Antihistamines must be stopped for five days.
- 02
Specific IgE blood test (ImmunoCAP)
Phadia ImmunoCAP is the preferred laboratory method. Used when SPT is contraindicated: dermographism, extensive eczema, ongoing antihistamines, or a needle-averse child who prefers one draw to multiple pricks.
- 03
Component-resolved diagnostics (CRD)
ImmunoCAP ISAC, ALEX2 or single Phadia components (Ara h 2 for peanut, Gal d 1 for egg, Cor a 14 for hazelnut, Jug r 1 for walnut) improve specificity and risk-stratify anaphylaxis versus pollen cross-reactivity.
- 04
Oral food challenge (OFC)
The gold standard for definitive diagnosis. A hospital day-case with escalating doses under paediatric allergist and anaesthetic cover. Confirms tolerance, defines threshold, and unlocks reintroduction where SPT and IgE are equivocal.
- 05
Atopy patch test
For eosinophilic oesophagitis (EoE) and delayed non-IgE hypersensitivity. Allergen patches worn for 48 hours, read at 72 hours. Used selectively alongside gastroenterology and dietetics.
- 06
Tryptase
Drawn during an acute reaction (ideally 1 to 3 hours after onset) and at baseline. Elevated tryptase supports anaphylaxis; a persistently raised baseline prompts a mastocytosis workup.
Common paediatric food allergens
- Cow's milk protein
- Egg
- Peanut
- Walnut
- Hazelnut
- Cashew
- Pistachio
- Almond
- Brazil nut
- Macadamia
- Sesame
- Soy
- Wheat
- Fish
- Shellfish
- Kiwi
Environmental allergens
- House dust mite
- Cat
- Dog
- Grass pollen
- Tree pollen
- Mould
- Cockroach
After diagnosis: living well with allergy
A diagnosis is not the end of the workup. A good allergist sets up avoidance (label reading, cross-contact, safe eating out), prescribes adrenaline autoinjectors with a written BSACI action plan, arranges a medic alert and school action plan, and refers to a paediatric dietitian to protect growth. For high-risk infants, early introduction of peanut and egg between 4 and 11 months is actively encouraged, following the LEAP, EAT and PEBBLES protocols.
Reintroduction is structured through the milk ladder and egg ladder. For persistent peanut allergy, Palforzia (NICE TA790) is NHS-approved oral immunotherapy; multi-food OIT is available privately.
Indicative pricing
Honest ranges across our London network.
| Test | Indicative range |
|---|---|
| Initial paediatric allergy consult (45-60 min) | £280-£450 |
| Skin prick test panel | £180-£350 |
| Specific IgE panel (ImmunoCAP) | £180-£380 |
| Component-resolved diagnostics (ISAC / ALEX2) | £380-£850 |
| ImmunoCAP, single allergen component | £45-£95 |
| Oral food challenge (hospital day-case) | £850-£1,600 |
Where we refer
- Great Ormond Street Private Allergy
- Evelina Children's Private Allergy
- Royal Brompton Private Paediatric Allergy
- St Mary's Imperial Private Paediatric Allergy
- Nuffield Health Paediatric Allergy
- BSACI-registered independent paediatric allergists
Related
Guides that pair with this one.
Frequently asked
Answers before you enquire.
-
What age can my child be skin prick tested?
From around six months. Younger infants can still be assessed with specific IgE bloods and a careful history. A BSACI-registered paediatric allergist will decide based on skin condition, medications and the clinical question.
-
Is IgG food intolerance testing useful?
No. IgG panels are not evidence-based and are not endorsed by BSACI, EAACI or the NHS. They generate false positives that lead to unnecessary food elimination, poor growth and anxiety. Skin prick, specific IgE and, where needed, oral food challenge are the validated tools.
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Will my child outgrow their food allergy?
Many outgrow milk and egg by age five, and roughly one in five outgrows peanut. We retest annually with SPT and specific IgE; when levels are falling and the history is stable, a hospital oral food challenge confirms tolerance.
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Should high-risk babies eat peanut and egg early?
Yes. The LEAP and EAT trials, and PEBBLES for eczema, show that early introduction between 4 and 11 months reduces peanut allergy in high-risk infants. Babies with severe eczema or egg allergy are assessed first, then introduced under the LEAP protocol.
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Does my child need an adrenaline autoinjector?
Anyone diagnosed with an IgE-mediated food allergy at risk of anaphylaxis is prescribed two autoinjectors, a written BSACI action plan, and a school plan. Component-resolved testing helps stratify who is at highest risk.
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How long does an oral food challenge take?
A full day at hospital, usually 4 to 6 hours, with escalating doses every 20 to 30 minutes, monitored by a paediatric allergist with anaesthetic and resuscitation cover on site.
Speak to a paediatric allergist
A clinician-led route to the right test, in the right week - not a scattergun panel.
Tell us what happened. We match your child to a BSACI-registered paediatric allergist at a vetted London clinic within one working day. Free.