The only condition I can think of which comes close to what you're describing is scabies. But scabies is a mite infestation that other family members would have by now.
Has your son seen a skin specialist? Has he had any blood tests, liver or otherwise? If not, I'd recommend both these approaches. (I doubt liver disease very much, but unless he gets a blood test, you won't know for sure.)
Best.
Dr. Rockoff
He was treated for scabies just as a preventative, but they didn't think he really had it b/c it did not help.
We're very much at the end of our rope. He has been suffering like this for almost 2 years now, with these periods of severe itching, worse at night, worse when he defecates, and obviously when he's stressed. No one can seem to help us. We've seen dermatologists, allergists, homeopaths and naturopaths all to no avail. No one seems to have any clue why he gets this itching and eventually scabs and bleeds from so much itching.
try using distilled water to wash with