Patch testing is a way to test for allergies, or for certain things that may be causing an allergic rash on your skin. Very small amounts of the possible offending ingredients are mapped out and placed on your skin in small patches. The most common place to apply these is on the back.
The patches are removed the reactions are read at various time points. The entire process takes about 4-5 days and 3 separate clinic visits. By eliminating the things your skin reacts to from your personal products, we can often prevent the rash from recurring.