How To Get Rid Of Dark Brown Patch On Leg?

I have a white circle patch on my leg that has a round red circle in the middle. The skin around the patch is dark brown. The red circle seemed infected and didn't heal and would get a white crusty scab to it. The dermatologist said that I may have had an allergic reaction to the neosporin I put on it and gave me clobex lotion to put on it. It healed the middle red spot so it no longer gets gooey or the white scab but there is still the outlying brown around the white circle which is around the red circle.