I've had shingles. I've also had various kinds of shoulder pain, some of it severe. Each time the shoulder flares up it feels different because there's so little space within the shoulder area for soft tissue to swell even a little bit. A muscle spasm or bursitis can put pressure on nerves, on tendons and ligaments and on muscles. If it pressures a nerve, it can feel like your skin is on fire. And like I said, the same old injury can cause different pain each time it flares up depending on what's getting impinged by inflammation and swelling.

Whatever you had on your leg, it probably wasn't shingles. Shingles is caused by the chickenpox virus and antibiotics don't help it at all. Shingles can cause long-term nerve pain along neural pathways but it's highly unlikely shingles on your leg would cause post-shingles pain in the shoulder.

If there's any chance you could have shingles in the shoulder area, you might ask your doctor for an anti-viral like acyclovir or famvir. The sooner shingles is treated the less likely you are to have long-term pain. Do you have anything on your shoulder area, on the skin surface, that looks like a cold sore or reddish blotch? If you do, it would be good to go back to the doctor.

Hope this heals quickly!