Terrible Rash - Doctors Puzzled - Help

[pzbp]

Hello,
I'm posting for my nephew.  He is 26 yrs. old.  He had asthma as a kid.  He is allergic to almost everything.  Can not use anything different.
All this started with a rash from shaving along his jaw line and neck.  Large bumps with some discharge.  The rash then spread.  He had this in his nose, ears, underarms and back. Then his neck and face swelled to the point where he looked like he had no neck.  
He went to doctor who said he had a severe infection and thought that it could be a allergic reaction.  Almost put him in hospital. Put him on antibiotics and steroids. Took biopsy of sores and blood work.  It has cleared up all except for the rash under the arms.  He says that it itches so bad and is not getting better.  He is scheduled for an allergy test in a month.  After seing the doctor again, blood tests and biopsy  normal, the doc told him he did not know what it was.  
He is a truck driver, self employed with no insurance.  This is his busy season.  Doctor kept him at home for awhile, now back to work.
Any idea what this is?  Could this be from asthma?  Any info would be great!  Thank You

[Deeds]

How much sucralose does he eat? It's real name is Splenda and is now in everything and sometimes in things we don't even realize. Splenda ((aka Sucralose)) has been known to be the culprit of many new and uneplained rash &  itching cases.

[Deeds]

How much sucralose does he eat? It's real name is Splenda and is now in everything and sometimes in things we don't even realize. Splenda ((aka Sucralose)) has been known to be the culprit of many new and unexplained rash &  itching cases.

[pzbp]

He drinks alot of Mt. Dew.  Just recently he started drinking diet root beer.  I asked him if he changed before the symptoms occured and he told me that the rash was there before he changed.  
He is a truck driver.  He hauls logs in the winter and then in the spring he hauls mulch and top soil.  He goes to the plant and picks up loads daily.
Could there be a connection with something in the mulch?
The mulch is hauled in bags but when he goes to the plant it is packaged there.
Could he be coming into contact with something there?
How do you figure out what the allergic reaction is?
He has to work.  If it is a reaction to the mulch, how does he cope?
Thanks

[Deeds]

yes - you can be allergic to mulch. He should get allergy tested. Does Benedryl help the syptoms (symptoms) go away?

[Deeds]

Yes, you can be allergic to mulch and anything sprayed on it too...he should ask for some mulch (put it in a baggie) and ask to be tested against it...People can have horrid allergies to wood pulp, wet or dried wood and pulp - it's not uncommon but, if he's inhaling large amounts of the mulch dust created by the warehouse and dumping it into his truck - I'd bet it's something to do with the mulch!  Keep us posted!