Skin Prick Testingfor Children in Belfast
Skin prick testing (SPT) is the gold standard for diagnosing IgE-mediated allergies in children. Quick, safe and well-tolerated from birth, with results available in 15–20 minutes. Performed by Dr Mugilan Anandarajan (FRCPCH) at Kingsbridge Private Hospital, Belfast.
From birth
Safe at any age
15–20 min
Results time
Same-day
Results available
30+ allergens
Can be tested
Safe, quick and well-tolerated — from birth onwards
What is Skin Prick Testing?
Skin prick testing (SPT) is the most widely used and clinically validated method for diagnosing IgE-mediated (immediate) allergic reactions. It works by introducing a tiny amount of allergen into the superficial layers of the skin and observing whether the immune system reacts.
In a child who is sensitised to an allergen, mast cells in the skin release histamine in response to the allergen, causing a small raised wheal (bump) to form at the test site within 15–20 minutes. The size of the wheal correlates with the degree of sensitisation.
SPT is preferred over blood tests as a first-line investigation because it is faster (results in 15–20 minutes rather than days), more sensitive for many allergens, and allows multiple allergens to be tested simultaneously in a single appointment.
When SPT is the preferred test
- Suspected IgE-mediated food allergy (immediate reactions)
- Suspected aeroallergen allergy (hay fever, asthma, perennial rhinitis)
- Investigating eczema triggers in young children
- Assessing sensitisation before allergen immunotherapy
- Monitoring changes in sensitisation over time
How the Test is Performed
Allergen drops applied
Small drops of standardised allergen extracts are placed on the inner forearm (or the back in very young infants), spaced 2–3cm apart. A positive control (histamine) and negative control (saline) are always included.
Skin pricked through each drop
A sterile single-use lancet is used to gently prick the skin through each allergen drop. The lancet penetrates only 1mm — the sensation is a light scratch, not a needle injection.
Wait 15–20 minutes
The allergen drops are left on the skin for 15–20 minutes. Your child can sit comfortably during this time. The arm should not be rubbed or scratched.
Wheals measured and recorded
Any wheals (raised bumps) that have formed are measured. A wheal of 3mm or more greater than the negative control is considered positive. Results are explained immediately.
Allergens Tested at Belfast Allergy Clinic
Dr Anandarajan uses a comprehensive panel of standardised allergen extracts alongside fresh food where clinically indicated. The specific allergens tested are tailored to your child's clinical history.
Food Allergens
- Cow's milk (fresh + commercial extract)
- Egg white & egg yolk (fresh)
- Peanut
- Cashew, walnut, almond, hazelnut, pecan, pistachio, Brazil nut
- Wheat flour
- Soy
- Cod fish, salmon, shrimp
- Sesame
Aeroallergens
- Grass pollen mix (Timothy, Rye, Meadow)
- Tree pollens: birch, alder, hazel, ash, plane
- Weed pollens: nettle, mugwort, plantain
- House dust mite: D. pteronyssinus, D. farinae
- Cat dander (Fel d 1)
- Dog dander (Can f 1)
- Mould: Alternaria, Cladosporium, Aspergillus, Penicillium
Controls & Other
- Positive control: histamine (10mg/ml)
- Negative control: saline
- Latex
- Bee venom, wasp venom
- Fresh fruit / vegetable (prick-prick technique)
Fresh food testing (prick-prick technique)
For certain foods — particularly fresh fruits, vegetables and raw foods — commercial extracts may underperform because the relevant proteins degrade during processing. Dr Anandarajan uses the prick-prick technique (pricking fresh food first, then the child's skin) for these allergens to ensure the most accurate results.
Understanding Your Child's Results
Interpreting skin prick test results requires clinical expertise. A positive test alone does not confirm clinical allergy, and a negative test does not always rule it out. Dr Anandarajan always interprets results in the full context of your child's clinical history.
Positive result
A wheal of 3mm or more greater than the negative control. This indicates sensitisation — the immune system has produced IgE antibodies to that allergen.
- Does not always mean clinical allergy — must be interpreted with history
- Larger wheals generally indicate higher degree of sensitisation
- May prompt further testing (CRD, specific IgE blood tests)
- Guides management and avoidance decisions
Negative result
A wheal less than 3mm greater than the negative control. This makes IgE-mediated allergy to that allergen unlikely — but does not rule out all types of allergy.
- Does not rule out non-IgE-mediated (delayed) allergy
- False negatives can occur if antihistamines were not stopped
- May prompt specific IgE blood test if clinical suspicion remains high
- Further investigation with specific IgE blood tests may be recommended
When blood tests are preferred over skin prick testing
Preparing for Skin Prick Testing
Stop antihistamines 3–5 days before
Antihistamines suppress the skin reaction and can cause false negative results. This includes cetirizine, loratadine, fexofenadine and chlorphenamine. If your child takes antihistamines regularly, contact the clinic for advice.
Continue all other medications
Inhalers, steroid creams, montelukast, nasal sprays and all other medications should be continued as normal. They do not affect skin prick test results.
Wear a short-sleeved top
Skin prick testing is performed on the inner forearm. Please wear or bring a short-sleeved top so the forearm is easily accessible.
Bring a reaction history
Write down any reactions your child has had — what food or substance was involved, how much was eaten, how quickly symptoms appeared, and what symptoms occurred. This is the most important information for the consultation.
Bring a distraction for younger children
A favourite toy, book or tablet can help keep younger children calm and still during the 15–20 minute wait for results.
Appointment details
- Duration60–90 minutes (including consultation and results)
- LocationKingsbridge Private Hospital, 811-815 Lisburn Road, Belfast BT9 7GX
- Also available atUlster Independent Clinic, 245 Stranmillis Road, Belfast BT9 5JH
- GP referralNot required — book directly
- InsuranceBupa, AXA Health, Aviva, Vitality, WPA, Benenden Health
- Self-payWelcome — contact clinic for fees
After the test
Any wheals from the skin prick test will settle within 30–60 minutes. Mild itching at the test sites is normal and can be relieved with a cold compress. Your child can return to normal activities immediately after the appointment.
Frequently Asked Questions
Conditions Diagnosed with Skin Prick Testing
Skin prick testing is used in the investigation of a wide range of allergic conditions in children.
Skin Prick Testing for Families Across Northern Ireland
Families travel from across Northern Ireland for skin prick testing at Kingsbridge Private Hospital, Belfast. Easily accessible from the M1, M2 and A1 with free on-site parking. No GP referral required.
Why parents choose Belfast Allergy Clinic for skin prick testing
- Consultant Paediatrician (FRCPCH)
- 25+ years clinical experience
- Children aged 0–16 years
- No GP referral required
- Allergy testing available
- Face-to-face and video consultations
- Recognised by major insurers
Book skin prick testing in Belfast
Same-day results. No GP referral required. Expert interpretation by Dr Mugilan Anandarajan (FRCPCH) at Kingsbridge Private Hospital.
Kingsbridge Private Hospital, 811-815 Lisburn Road, Belfast BT9 7GX