I have sciatica pain and now a rash on that spot. what does that mean?

Shingles?: It is hard to say without an evaluation and looking at the rash. Sometimes a one-sided rash that also has nerve pain with it could be a shingles outbreak. However, i think that it could be a whole variety of different things as well - or the sciatica and the rash may not be related at all. Perhaps it's just best to have someone take a look and evaluate it.

Shingles: This sounds like you have developed shingles (herpes zoster). This could have caused your initial pain prior to the rash. This can be treated, so see your doc asap.

Shingles?: Not typical for sciatica to cause a rash. However Shingles is possible and can cause sciatica like symptoms. See your doctor to make sure.