Spider bite, Shingles, or Fungal infection?

What a full couple of weeks we've had.  Troy did a side job for my sister, putting in a new furnace and a/c unit.  After 2 days in a crawl space under her house Troy found a circular rash on his arm and 2 on his back.  He doesn't remember feeling bit.  He didn't think much of it but after a week it had all grown and joined together into a giant rash.  I won't go into to many details or post pictures, it's pretty gross.  His brother and I finally convinced him to go to the doctor.  Who claims whatever it is, is infected.  He was prescribed high doses of antibiotics.  It seemed to be doing better, sort of.  We had my brothers wedding on Saturday and Troy's rash didn't grow much.  Sunday the rash started to get worse again.  We call the doctor and she's out for the week.  We see a different doctor who prescribed more antibiotics which specializes in the Mercer staph infection.  He has also had a blessing.  Today it has grown even more.  The doctor did take samples on Monday and we should know what it is come Wednesday night.  Unfortunately Troy has been feeling flu like symptoms now and isn't sure if the two are related.  Of course because Troy is sick he has problems at work and can't stay home to rest.  I pray that they find out what is wrong.  Please put Troy into all your prayers for us.  Thank you!