Which Specialist Should I Consult For Redness In The Groin Area?

My husband has recently been hospitalized for a broken leg, received in a hit and run accident. Since he has been laying in bed a lot, he has developed a very red area in his entire crotch, including testicles, and the skin on his legs, nearby . We have tried triple antibiotic ointment, baby powder, and Vaseline. Powder helped a bit. This has been like this for two weeks, and not getting better. What do you suggest? Because he s in a wheelchair, he has not been proactive in dealing with this secondary problem, but, now, it s definitely become a nuisance. It doesn t itch, but, it is tender, and slightly sore. Do we see a dermatologist or a urologist, if it gets to that point. He is 75 years old, and also having trouble with urination, both emptying his bladder, and being able to pee when he gets the urge.