Suggest Treatment For Swollen Area On Arm And Elbows

I have a swollen area on the inside of my arm on the other side of the elbow. It is above the crease and on the right side. It has been there for about two to three weeks and does not hurt, itch or bother me. I have been diagnosed with Graves disease/Hyperthyroid and parathyroidism. I am taking one 5 mg tablet of Methimazole. I have also developed Polymyalgia and am taking 10 mg of Prednisone. What do you think would be causing the swelling?