Patch Testing: The Basics -Robin Lewallan M.D., Board Certified Dermatologist

Patch testing is a non-invasive procedure that helps dermatologists identify the substances that trigger an allergic reaction on your skin. It involves applying small amounts of suspected allergens, called haptins, onto your skin, usually on your back, and leaving them there for a couple of days to see if a reaction occurs. If you suffer from persistent skin irritation, rashes, or other skin conditions, your dermatologist may recommend patch testing.

Here’s what you need to know about patch testing.

Who should consider patch testing?

Patch testing is recommended for people who have a persistent skin condition that has not responded to treatment. It is particularly useful for people with eczema, contact dermatitis, and other allergic skin reactions. Patch testing can help identify the specific allergens that are causing the reaction, allowing you to avoid them in the future.

How is patch testing performed?

Patch testing is a simple and painless procedure. Your dermatologist will place small patches containing a variety of suspected allergens on your back. The patches will be left on for about 48 hours, and you will be instructed to avoid getting them wet or engaging in activities that could cause excessive sweating during this time.

After 48 hours, the patches will be removed, and your dermatologist will examine the skin under each patch for signs of a reaction. A reaction could present as redness, swelling, or a rash.

After the initial examination, you will need to return to the clinic for another examination after 72-96 hours. This is to ensure that delayed allergic reactions are also identified.

What happens after patch testing?

After patch testing, your dermatologist may be able to identify the substances or allergens that are triggering your skin reaction. They will then provide you with advice on how to avoid these allergens and recommend alternative products that are safe for your skin.

In some cases, your dermatologist may also prescribe medication to alleviate your symptoms. It is important to follow their advice carefully to ensure that your skin condition is effectively managed.

If you have a persistent skin condition that has not responded to treatment, patch testing may be recommended. It is a simple and painless procedure that can help identify the specific allergens that are causing your skin reaction. By avoiding these allergens, you can effectively manage your skin condition and enjoy healthier skin.

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