My wife had terrible joint pain and it was from the Remicade. They sent her to the Rhemuatologist, tested her for a few other things including Lupus.
For her, it seemed to be mostly in her hands and elbows, but moved around different places like her neck and ankles. There was also swelling and red irritation in her joints.
It seemed to go away when she got her Remicade treatment, but turns out that it wasn't the Remicade helping her, it was the small dose of Preds they were giving her before her treatment.
The good news was it was all reversible once she was taken off Remicade. After several weeks, she was fine.
They moved her to Humira and everything is back to normal. Her crohn's never flared during this period.