I have optic neuritis (2 months about 90% vision returned). i now have a "sunburn" type feeling on my leg (skin isn't red). could it be related?

Very likely: The skin and nervous system originate from the same embryonic tissue often showing signs of inflammation when one or the other is affected. Also, this could be interpreted as a paresthesia (a symptom of inflammation of skin nerves) clearly showing an association. Multiple sclerosis comes to mind, please check with your neurologist to be sure this isn't significant.

Yes: About 1/3rd of people with optic neuritis develop multiple sclerosis. This "feeling" could be a manifestation of that. I suggest making an appointment with a neurologist soon.