Can Taking Clopidogrel Blood Thinner Cause Hives

I have had Hives for 9 years. It settled down but would relapse about every month and only affect my lower legs. In Febuary I had 2 cardiac stents put in and i was put on metropolol for heart palpations and irregular heart before they found the blockages. Also clopidogrol Blood Thinner. Afte starting these medications the hives have come back om upper and lower legs, arms, back, torso. I think the meds have brought it on but my Dermatologist is not so sure.Its been 7 months straight now.