Unexpected trip to urgent care

Just back from urgent care.  Drew got bit by a spider (we think) and it's all infected.  At 3:00, I noticed he had a bite on his leg about the size of a quarter.  I gave him Benadryl and didn't pay much attention to it.  At five thirty I happened to see it and it was bright red and four inches around the initial spot.  I felt it and it was hot.  And seeping.  Went to urgent care after Eric got home from work.  Poor Drew had some difficulty when the receptionist made me stop him from opening and closing the doors.  By the time the doctor saw him, there was a red line radiating down from his bite and he had fever of 99.9 degrees. She prescribed some antibiotics and cream.  She was very good with him. She sat right down on the floor with him to examine it.  When we got home we put a warm compress on it as she instructed and gave him his medicine.  I applied the cream and he is now watching Alvin and the Chipmunks.  I think it's hurting a bit because he keeps asking, "It feels better?"  I did give him some Advil for the pain.  Poor fella!