Skin Prick Test
A skin prick test (SPT) is a commonly used test for diagnosing allergies. It helps to identify potential allergens (substances that trigger allergic reactions) in an individual experiencing symptoms like sneezing, itching, hives, persistent cough or difficulty breathing.
During the test, small amounts of potential allergens are introduced into the skin using a tiny needle or lancet. These allergens can include common triggers such as pollen, pet dander, mold, dust mites, insect protein (e.g. cockroach) and certain food items like egg. By pinpointing specific allergens, SPT can help doctors develop an effective treatment plan, which might include lifestyle adjustments, or immunotherapy.
What to expect and how to prepare for SPT?
- The procedure for SPT typically takes only about 25 to 30 minutes.
- Before the test, you may be asked to stop taking antihistamines or other allergy medications for a few days, as these can interfere with the results.
- The test is usually performed on the forearm or back. A small drop of each allergen extract is placed on the skin.
- Using a tiny needle or lancet, the skin is pricked through each drop to allow the allergen to enter the skin. This may cause mild discomfort, but usually doesn’t cause pain.
- The test is typically performed with multiple allergens at once, allowing for a comprehensive assessment.
- The area is observed for signs of a reaction. A raised, red bump (similar to a mosquito bite) indicates a positive reaction. The size of the bump is noted to determine the severity of the allergic response.
- The test results are usually available immediately. The allergist will interpret the reactions to each allergen and discuss the findings with you, helping to create a tailored treatment plan.
Is the Skin Prick Test Safe?
The skin prick test is generally safe. There may be rare complications, which will be discussed with you before performing the test.