Why do a skin prick test?
Skin prick testing (SPT) is usually the preferred way to diagnose IgE mediated allergies. Our staff at the Children’s Allergy Clinic are trained in performing SPT. The SPT results should always be interpreted in conjunction with your child’s history.
How long does it take to get the result?
You receive the results on the day of your appointment as the test only takes about 15-20 minutes.
What does a skin prick test involve?
Small amounts of allergen are introduced into the superficial layer of the skin (epidermis) with a quick and minor scratch. The allergen interacts with specialised immune cells that may be residing here, called mast cells. Histamine and other mediators are released from these cells, leading to a visible "wheal-and-flare". This wheal and flare appears as redness and swelling. This is measured and then interpreted by the allergy specialist.
Risks
The test itself is fairly painless. It can commonly cause very mild itching, which is short-lived. The most important risk to consider, though minimal, is a systemic allergic reaction (anaphylaxis). There is always a doctor on site who will be there to manage this if it were to occur.
Medications to stop before a skin prick test
We recommend that antihistamines (Claratyne, Zyrtec, Telfast, Aerius) are stopped prior to skin prick testing as they can interfere with the skin prick testing results. Please contact the clinic and ask how long your child needs to be off their antihistamine before their SPT.
Other tests
Serum specific IgE testing or 'RAST' testing is available. However this can be distressing, as your child needs a blood test at a pathology centre. We prefer skin prick testing as it is more sensitive. There as some instances where SPT may not be able to be performed and we may have to consider a blood test to investigate your child’s allergy.
