Suggest Treatment For Circular Spontaneous Bruises On My Abdomen

I began to get circular spontaneous bruises on my abdomen about a week ago. The circle is unbruised in the center. I am 67 years old, have asthma which is being treated with a cortisone inhaler and am taking high blood pressure medications, one of which is diltiazem. I drink 2 glasses of white wine each day. I also have arthritis, which up until now was thought to be osteo, not rheumatoid. Can any of these factors cause this type of bruising?