How is patch testing used to diagnose contact dermatitis?
To diagnose allergic contact dermatitis, a doctor may attach very small amounts of different substances to the skin on the back or arms using a special type of tape. After two days, the patches of tape are removed and the skin is inspected for any signs of an allergic reaction. As most reactions take days to develop, the skin is usually examined again four to six days later.
Author: Lauren Donley
First answered: 23 Sep 2014
Last reviewed: 19 May 2018
Rating: 4.4/5 Votes: 398