How To Prevent Abscess From Getting Worse Until Further Treatment?

My friend had a horrible work comp injury where he had a titanium rod placed near his ankle. He has been weaaring a verlcro boot to help him walk and it seems to have been rubbing up and aginst his ankle. It currently is leaking - he is afraid that it is turning into an abscess. We got sterile wipes and gauze until he can get to his doctor in the morning - is there any way we can prevent it from getting worse