For about two weeks I ve had this disgusting looking scab on my lower leg. I m not sure if it is a scab, blister, or etc. When it started to form, it was itchy. Now, it is a open sore with yellow looking blotches sticking up. My leg is sorta swollen and it has a slight redness around it. I m not sure what it is. I might get it checked out, but not sure if it is major. Please respond back, really worried.