My first episode of RP was costochondritis; I agree that it's extremely painful, but then...the ear attacks are no picnic, either. Like you, I also have RA, so it's hard to know which is causing the joint pain. My general feeling is that I don't care as long as I can control it. My monthly abatacept (Orencia) infusions for RA seemed to reduce the frequency of the RP flares (mostly ear attacks, some costo and nose attacks), but my rheumatologist (central Massachusetts) is only mediocre. I haven't found a good one nearby and don't know a soul in Iowa, so I'm sorry I can't help.