Problems after angiogram/angioplasty

My father had an angiogram, and 2 angioplasty procedures with a total of 3 stent placements in the past 4 weeks.  He had an allergic reaction to something following the last angioplasty----swelling of jaw, face, and generalized swelling and itching all over.  That has resolved but starting suddenly 2 weeks after the last procedure, he has severe, generalized joint stiffness and pain.  His right knee is swollen and very painful.  The only thing new since his angioplasties is that he was placed on Plavix.  

Could this be from Plavix?  Would this have anything to do with the allergic reaction?

[CCF HeartMD-2]

There seems to have been two different processes, the first one sounds like an allergic reaction to some medication which has resolved and the second one with swollen and inflamed joints could be related to many other things.  It would be dangerous to stop plavix with recent stents so this medication should not be stopped. The painful and swollen joint should be evaluated promptly to ensure there is no infectious or inflammatory process in the joint which could be treated.