Anyone heard of Stevens-Johnson Syndrome?

Sometimes this skin reaction is related to radiation therapy.
my boyfriend checked into the hospital tonite to undergo the placement of his feeding tube
and txted me to look it up. Depressing to say the least.
Dont know who told him about this, why, as far as if they think he has that, or what.
His skin is all blistery, somewhat painful and red and peeling. Thats about all I know.

Anyone have any clue?