Elderly Pot-Belly Skin Disorder

Question
At a rescue organization where I volunteer there is a Pot-Belly
who has always had a terrible skin condition.  Mr. Crusty
develops large round skin growths that hang off his body.  The
growths are mostly on his belly rear, and neck. Some are as
large as 4 inches in diameter hanging 4 inches off his body.
Smaller ones look like very large warts.  They are only raw if he
rubs up against things in an attempt to scratch.   The condition
is not contagious, as he lives with other pigs who do not
contract the disorder.  A local vet does not know what is wrong
with him, saying only that there is nothing she can do about it.  
Have you ever heard of anything this severe? Do you know of
any treatments?  Any help would be greatly appreciated. Thank
you.  

Answer
I must say I've never heard of a condition like this, either. The Dutchess Fund www.dutchessfund.org has a veteranary database, it's possible they might have seen something similar.
Bag Balm might help with the itching. Make sure no insects are biting him by using a repelent on him. I use an ordinary human repelent, the unscented liquid pump kind, warmed slightly in warm water (pigs hate being sprayed with anything cold).  
Has he been treated for mange, with Ivomecterin or similar? If not, I'd try that, because it can't hurt. Some pigs are just more susceptible to mange, and require more frequent treatments or include treated 2% cornmeal in their diet.
Have these lumps been biopsied?
If it's ok with you I'd like to pass this question along to some of my pig groups. I have a few more questions, too.
Soil born parasites can thrive in some climates and not survive others. Where are you located, and do you know where Mr Crusty came from? I am guessing he arrived with this condition? How long have you had him, and any guesses about how long he's had this condition? How old is he? I assume he's neutered?
Please feel free to email me privately at helen_morrison@yahoo.com