Skin Prick Tests (SPT)
What is skin prick testing?
Skin prick testing or SPT demonstrates an allergic response to a specific allergen and can help to confirm the presence of an allergy to either a food or inhaled substance (allergen). It is a simple, safe and quick test, showing results in just 15 to 20 minutes, and therefore enabling practitioners to provide diagnosis and management plan for a patient during their appointment.
What happens during SPT?
SPT introduces a tiny amount of allergen under the skin, eliciting a small, localised allergic response, in the form of a wheal (bump) and flare (redness) at the site of testing. These tests can be carried out on all age groups, including babies.
These tests are useful if we think a child has had an IgE-mediated reaction. Typically, a child on exposure/eating something they are allergic too, a reaction occurs within minutes and symptoms include:
- swelling
- itch
- nettle rash
- vomiting
- sneezing
- wheezy chest
Can be useful to find triggers in eczema
Can test for the following:
- animal hair
- house dust mite
- moulds
- pollens
- common foods including nuts/milk/egg/soya/fish
They are NOT useful for intolerances. There is NO test for intolerances and the treatment is to stop eating the suspected food for 4 weeks. If symptoms (classically bloatedness/tummy pain/loose stools) get better, BRING the food back to make sure problems then return to diagnose the cause.