Tiny drops of purified allergen extracts are scratched into your skin’s surface (virtually pain free, no needles). The site is then monitored for the development of redness and swelling (a positive looks like a mosquito bite) at the site of administration over the next 15-20 minutes.
A patient’s IgE, the allergy antibody, is measured against a specific allergen. This is considered slightly less reliable than the SPT because there is a higher false positive rate than the SPT (a smaller chance that a positive test will correlate with symptoms). A negative test is similar as SPT. This study is sent to a laboratory therefore the results take approximately 1-2 weeks (SPT results are available in 15 min). This test is generally used when there are other factors that preclude the use of the SPT such as severe atopic dermatitis (eczema), anaphylaxis to the suspected food, patients that cannot discontinue antihistamines.
Allergy skin tests are widely used to help diagnose allergic conditions, including: