An online friend has this rare disease. Is there anything he can do for it? They have him on steroids.
"I have a very rare thing call pemphigus vulgaris – my immune system (body/ego identity) is attacking itself (vicious). I have blisters and sores in my mouth and nose and all over my upper body. I could not eat, and finally I could not drink."
This is an autoimmune condition, which in part will stem from weak adrenal glands leading to the overproduction of low affinity (nonspecific) antibodies, also known as "autoantibodies". Steroids and other immune suppressants are the worst things that can be done for autoimmune conditions. These drugs will suppress the symptoms, but will also make the underlying condition worse in the process. Make sure he is aware though that he cannot simply go off of steroids "cold turkey" since the steroids shut down the adrenal glands.
Have him read my write up on autoimmunity for starters: