Infectious Disease and ... ?

As name of this threat suggest, what I am asking in if there is anything that can be combined with Infectious Diseseases and why would that one combination be good with it. Like, for example only, Dr. House is ID and nephrologist, I dont know if it is only to show that hes genius or if ID and Nephrology can be combined. Is there something else that can be combined with Id? like critical care or something? I hope I made myself clear enough :/ Thanks for answers in advance
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Source Type: forums