What the test is looking for
Patch testing helps a clinician investigate whether a substance touching your skin may be contributing to a delayed skin reaction. Small amounts of test substances are placed under patches, usually on the back.
It is different from a skin prick test, which looks for an immediate response. Patch test reactions can take days to develop, so the full sequence of readings matters.
The appointments
Your clinic will explain its own schedule. A common approach is to keep the patches in place for about 48 hours, return for removal and an initial reading, and then return again for a later reading. Some reactions appear only after the first visit.
Follow the instructions from the clinician who applied your patches, including how to care for the test area and when to return. Do not change the schedule based on an app or website.
Where tele-derma fits
A clear set of photos can help you keep a visual record between appointments. tele-derma is designed to help you organize and review those images. Your clinician remains responsible for interpreting results and deciding what they mean for your care.