When Should My Child Have Allergy Testing? A Parent's Guide

What allergy testing can and cannot tell you

Allergy testing identifies whether your child's immune system has produced IgE antibodies to specific allergens (sensitisation). A positive test result, combined with a consistent clinical history, confirms an IgE-mediated (immediate) allergy. However, a positive test alone does not always mean a clinical allergy — results must always be interpreted by an experienced specialist alongside the full clinical picture. Testing cannot reliably diagnose non-IgE-mediated (delayed) food allergies, which are diagnosed through elimination and reintroduction protocols.

Signs that allergy testing is recommended

• Your child has had an immediate reaction (hives, swelling, vomiting, breathing difficulty) after eating a specific food
• Your child has had anaphylaxis — a severe, life-threatening allergic reaction
• Your child has eczema that is not responding to standard treatment
• You suspect a food is triggering or worsening your child's eczema
• Your child has persistent rhinitis (runny or blocked nose) year-round or during pollen season
• Your child's asthma is triggered by specific environments, seasons, or allergen exposures
• Your child has urticaria (hives) that is recurring or unexplained
• You want to introduce a high-risk food (e.g. peanut) to a baby with eczema
• Your child has been avoiding a food and you want to know if it is safe to reintroduce
• Your child has multiple suspected food allergies

When testing is NOT needed

Not every child with a suspected food reaction needs formal allergy testing. If the reaction was mild, isolated, and clearly linked to a food that has since been safely reintroduced, testing may not add value. Similarly, for non-IgE-mediated conditions such as reflux, colic, or blood in stools in infants, standard allergy blood tests are often negative and a different diagnostic approach is used. Dr Anandarajan will advise on whether testing is appropriate for your child's specific situation.

What types of allergy testing are available?

• Skin prick testing (SPT) — the gold standard for IgE-mediated allergy; results in 15–20 minutes
• Specific IgE blood tests — measures allergy antibodies; useful when SPT is not possible
• Component-resolved diagnostics (CRD) — identifies specific proteins causing the reaction; improves risk stratification
• Patch testing — for contact allergens causing delayed skin reactions

What age can allergy testing be done?

Allergy testing can be performed at any age, including in newborns and young infants. Skin prick testing is safe and well-tolerated from birth. The type of testing recommended depends on the child's age, symptoms, and clinical history. Dr Anandarajan has extensive experience testing children from infancy through to adolescence.

What to expect at an allergy appointment

A standard allergy assessment at Belfast Allergy Clinic takes approximately 60–90 minutes. Dr Anandarajan will take a detailed clinical history, perform appropriate testing, interpret the results in the context of your child's history, and provide a personalised written management plan. You will leave with a clear understanding of your child's allergy status and what to do next.

Do I need a GP referral?

No. You can book directly at Kingsbridge Private Hospital or Ulster Independent Clinic without a GP referral. If you have any previous test results or a letter from your GP, it is helpful to bring these along, but they are not required.