I Have Several Areas Around My Body Which Are Skin

I have several areas around my body which are skin problems of some sort. Blotchy, mildly itchy, have had them for 3 or 4 months. Mostly around lower part of both legs; 3 inches or so wide, 1 or 2 are smaller. Also upper part of both arms, blistery, redish. PCP dr. looked and said not to worry about it. But it persists and is not improving. Suggestions? Thank you.
Incidentally, I am a 80 yr old male, normal blood levels although BUN is 2.0