Patch Testing

At Village Dermatology in Houston, we perform extensive patch testing on patients with possible skin allergies.

What is patch testing?
Patch testing is a test to assess your skin’s reaction to substances with which you may come into contact at work or at home. Typically, these substances are those that are found in metals, clothing, dyes, and cosmetic products. Small patches are placed on your back consisting of various chemicals that are the most likely to cause allergic reactions. The patches adhere to your back with hypoallergenic paper tape.

This procedure does not involve any needles or “pricking.” That type of allergy testing is different in that it checks for food allergies or airborne allergies, and it is typically done by an allergist or ear/nose/throat doctor. Patch testing is not meant to cure your skin ailment, but rather to give more information as to what might be causing or contributing to it. There is a possibility of a negative result (no allergic reactions), but this is also sometimes helpful to know.

Depending on the type of testing done, patch testing will require either 2 or 3 visits. Typically, the patches are placed on your back on a Thursday or Friday, removed by you at home on a Saturday or Sunday (48 hours after they are placed), and the reaction is read on either Monday or Tuesday. For the entire duration of the testing, you cannot get your back wet. The first office visit on typically can take 45 minutes to 1 hour, so please do not schedule this appointment at a time when you are rushed, and do plan to bring something to do while you wait.