Suggest Remedy For Itching Sores

In the past few months I have had several sores or bites and I want to keep scratching them because it it like a venom or poison so now I have several scars. Two nights ago I had a tiny place on my chin and the more I worked with it the larger it got and now it is the size of a nickel and burns all the time. I have used silversorb on it and have tried to let it air out but it burns.