Can I Take Coumadin For Rash Caused By A Bite?

I was bitten by a bee 2 days ago and have a rash that is approx. 5" in diameter on my calf area. It itches badly; have tried Ivarest that has calamine in it but have had no noticeable decrease in itch. I take coumadin for mechanical heart valves and wonder if it is a factor in the size of the lesion.