I used to work with a guy who had gotten bitten by a brown recluse on his thumb.
Doctors tried all sorts of treatments, finally got to the point of “If this one doesn’t work, we’re going to have to amputate your thumb”.
Fortunately, that last treatment worked.
I can’t comment on your friends situation. The bites are dangerous. But 90% of bites are not much worse than a mesquito bite. I put glue traps around my house a few years ago, got a few over a few months and have not seen them since. Good riddance.