Hi, may I answer your health queries right now ? Please type your query here..the skin on my thigh have had a terrible burning sensation for three weeks. Last week I had a root canal and the dentist said there was a bad abcess under the tooth. My face is now swollen and I am on 2 antibiotics. Could the underlying infection have caused the burning sensation on the skin on my leg. I am noticing red spots under the skin on my thigh also.