A few months ago I managed to gash my leg open and the edges of the cut had to be steri-stripped together. To protect and limit bleeding I put a large plaster (band-aid) on it. When the cut had healed enough for me to remove the plaster I found I had had an allergic reaction to the adhesive. I left the reaction alone as I am used to reacting to the adhesive of some plasters and the reaction will normally leave on its own in a few days. The redness of the reaction had died down but now I have a dark, tan looking, mark where the reaction was. I’ve done some research but can not seem to find the explanation for this. Hoping this isn’t too serious and can just be put up to my skin but I don’t know.