The skin prick test is one of the quickest and most reliable ways to find out what you are allergic to. Many patients feel nervous before the test, imagining injections or pain, but it is simple, safe and nearly painless. In this video, Dr. Dipak Viradia, Chest Physician & Intensivist, explains how the test is done and what to expect.

Before the Test

• Anti-allergy tablets (antihistamines) can block the test result. Your doctor will usually ask you to stop them for a few days before the test. Some other medicines may also need to be paused.
• Don’t stop any medicine on your own. Asthma inhalers and most regular medicines can usually be continued, but always confirm with your doctor.
• Avoid applying creams or lotions on your forearms on the day of the test.
• Tell the doctor if you are pregnant, have had a severe allergic reaction before, or have uncontrolled asthma.

How the Test Is Done

1. The forearm is cleaned and marked with small numbers or labels, one for each allergen being tested.
2. A tiny drop of each allergen solution (such as dust mites, pollen, mould, cockroach, cat or dog) is placed next to its mark.
3. The skin under each drop is gently pricked with a small sterile lancet, just enough to let the allergen into the very top layer of skin. It doesn’t go deep and usually doesn’t bleed.
4. Two control drops are included: a positive control (histamine), which should cause a reaction in everyone, and a negative control (saline), which should not. These confirm the test is working correctly.
5. You wait about 15–20 minutes.

Reading the Results

If you are allergic to a substance, a small, raised, itchy bump (called a wheal) with surrounding redness appears at that spot, similar to a mosquito bite. The doctor measures the size of each bump and compares it with the controls. A bump clearly larger than the negative control indicates sensitisation to that allergen.

Remember: a positive result shows sensitisation. Your doctor will match it with your symptoms to confirm which allergens are actually causing your problem.

Is It Safe?

Yes. The test is done under medical supervision and is very safe. Mild itching and redness at positive spots are common and usually settle within an hour. Serious reactions are very rare, and the clinic is prepared to manage them if they occur.

Patch Test: A Different Skin Test

The patch test is used for a different problem: skin allergy from contact (contact dermatitis), such as reactions to metals, cosmetics, hair dye or chemicals. Small patches containing these substances are stuck on the back and read after 2 days or more. It does not test for dust, pollen or nasal allergy.

After the Test

Based on the results, your doctor will advise how to avoid your specific triggers, which medicines are suitable, and whether allergen immunotherapy could help.

Dr. Dipak Viradia
Chest Physician & Intensivist | Interventional Pulmonologist & ECMO Specialist
Rudrax Chest Clinic, 301, Solaris Royce, Opp. Old RTO, Athwagate, Ring Road, Surat – 395001
Appointment: +91 75676 19985
Website: www.drdipakviradia.com