Allergy Testing

What is Allergy?

Allergy occurs when your body’s defense system reacts to a foreign substance — such as pollen, bee venom, pet dander, or certain foods — that does not cause a reaction in most people.

Your immune system produces substances known as antibodies. When you have allergies, your immune system makes antibodies that identify a particular allergen as harmful, even though it is not.

When you come into contact with the allergen, your immune system’s reaction can affect your skin, sinuses, airways, or digestive system.

The severity of allergies can vary from mild irritation to anaphylaxis, a potentially life-threatening emergency. While most allergies cannot be cured, treatments can help relieve symptoms.

What is Skin Prick Allergy Testing?

During allergy skin testing, your skin is exposed to suspected allergy-causing substances (allergens) and then observed for signs of an allergic reaction.

Along with your medical history, allergy tests may help confirm whether a particular substance you touch, breathe, or eat is causing your symptoms.

Why is it done?

Allergy skin tests are widely used to help diagnose allergic conditions, including:

• Hay fever (allergic rhinitis)
• Allergic asthma
• Dermatitis (eczema)
• Food allergies
• Penicillin allergy
• Bee venom allergy

Skin tests are generally safe for adults and children of all ages, including infants. However, in certain circumstances, skin tests are not recommended.

What to expect on the day of Skin Prick Allergy Test?

• A skin prick test, also called a puncture or scratch test, checks for immediate allergic reactions to multiple substances at the same time.
• This test is commonly performed to identify allergies to pollen, mold, pet dander, dust mites, and foods. In adults, the test is usually done on the forearm.
• Allergy skin tests are not painful. The lancets used barely penetrate the skin’s surface.
• A lancet is used to prick the allergen extracts into the surface of the skin.
• After about 15 minutes, the nurse observes the skin for signs of allergic reactions.
• If you are allergic to a substance, a raised, red, itchy bump (wheal) may appear, similar to a mosquito bite.
• The size of the reaction is measured and recorded, after which the skin is cleaned with alcohol to remove the marks.

Source: (Click Here)

When Skin Testing May Not Be Advised

Your doctor may advise against skin prick testing if you:

• Have a history of severe allergic reactions, as even small amounts of allergen can trigger life-threatening anaphylaxis
• Take medications that interfere with test results, such as antihistamines, certain antidepressants, or some heartburn medications
• Have severe skin conditions like eczema or psoriasis involving large testing areas
• Have dermatographism, which can cause unreliable test results

Blood tests (in vitro immunoglobulin E antibody tests) may be useful for individuals who cannot undergo skin testing. However, blood tests are not used for diagnosing penicillin allergy.

In general, allergy skin tests are reliable for diagnosing allergies to airborne substances such as pollen, pet dander, and dust mites. While skin testing may help diagnose food allergies, additional tests or procedures may be required due to the complexity of food allergies.