Suggest Treatment For Sensitive Swelling In Leg

My husband age 66 has a large inflamed area on his leg. It is very red, sensitive to touch with a small darkcylindrical spot toward the center. His pant leg seems to irritate it and he has had it for several days. THe spot has grown in size and gotten redder. He is unable to see his physician until late Wednesday. Is there anything that we can do in the mean time? Is it something that should not wait?