Have you ever undergone a SPT? SPT or skin prick test is used to check out the immediate allergic reactions of a person to a particular allergen. The test is usually conducted on the forearms of adults and the upper back in children. It follows a simple and safe process, with results arriving within 15 to 20 minutes. These skin tests are not painful, as the needles used hardly puncture the skin’s surface. These needles are also known as lancets.
Common Allergens
Some common allergens we all are aware about include:
- Pollens
- Certain foods
- The house dust mite
- Certain medicines and
- Animal dander or the tiny dead skin cells shed by animals
Suppose, you are allergic to any of these allergens discussed above. Your body’s response to the allergen can vary from very mild reaction to a serious life-threatening one. There are many dependable medical clinics in London that handle these tests in an excellent manner.
The Test Procedure
At the reputed medical clinics across Harley Street, the suspected allergens are first mixed with a liquid to form a solution. A drop of those solutions is then placed on the skin. The skin beneath the solution-drop is slightly pricked with a thin needle. Actually, the tiny prick, made by an expert hand, is enough to drive a little amount of the solution into the skin.
Observation Procedure
The skin is then carefully observed for a reaction. The reactions usually occur within half an hour of the needle prick.
- A reaction is ‘positive’ when the affected area of the skin turns red and itchy.
- In positive reactions, a white, raised swelling called weal or wheal appears too.
- It surrounds the reddish central area of the reaction.
- A wheal usually takes about 15 to 20 minutes to reach its maximum size.
- Then it starts fading away over a few hours.
On the other hand, the reaction is ‘negative’ when the affected area of the skin remains normal. A negative reaction indicates; you are not allergic to the allergen present in the solution.
Safety Measure in SPTs
According to medical experts, SPTs are safe as very small amounts of allergens are tested on a person’s skin. However, the test is usually not done on pregnant women, people having severe asthma, patients on certain medications and those who suffer from eczema.
Preparations for the Test
- You should tell the allergist about all the medicines you are currently taking, including those common ones not prescribed by your doctor.
- Stop taking any antihistamine for about 7 days before the test.
In fact, your allergist will guide you on this topic at the right time.
Additional Tests
If the skin reacts normally, allergist will apply two more substances on your skin, histamine and glycerin.
Most people are sensitive to histamine. If your skin does not react to it then, your SPT will not reveal an allergy even if you have one. Glycerin, on the other hand, does not cause any reaction on skin. If your skin reacts to it then, you have a sensitive skin.
Medical Express Clinic – The reputed Harley Street-based medical clinic is one of the most dependable centers for carrying out SPTs. At this clinic, you can be assured that your skin prick test result will be carefully observed to avoid a false allergy diagnosis. Providing quality service at reasonable cost is the key to success for this trusted clinic. You can book an appointment any time with this medical facility center and get your tests conducted safely and correctly.