They have ruled out other possibilities of infection. The infection is coming from the abscess area. He has been on heavy duty antibiotics for a week. They are adding an antifungal to see if it responds. In the meantime they will CT the area to see if there are areas of pus. If so they will operate again to drain it. If not they will see if he responds to antifungals and do a punch biopsy of the skin to make sure nothing dermatological was overlooked. Once his is on the right path for healing they will release him and continue to get the IV antibiotics at home.