Some other points about patch testing
Patch testing only tests for allergic contact dermatitis. It does not diagnose other types of allergy such as food allergy or urticaria.
Keep the area of skin being tested dry until the final skin examination - which is usually four days after the patches are put on the skin.
While patch testing is in progress, avoid activities that cause you to sweat a lot.
Patch tests are not the same as skin prick tests which are sometimes used to diagnose other types of allergy.
Patch testing cannot find the cause for atopic eczema.
Keep sunlight and other sources of ultraviolet (UV) light off the skin being tested. So, keep a shirt on when outdoors for the duration of the test.