回复：It's an autoimmune disorder

Immue system over react, instead of killing outside germs and virus, the immune system is killing the healthy tissue (your friend's skin). A lot of people here work and live with auto-immune disease. New bio-logical drugs can control the syptom, but not cure. The disease will not go away, but the patient can rehab the immune system to reach a balance. Remicade , humira are common drugs in auto-immune treatment, but those are all presription drugs, you freind needs to see a Immunologist or Rheumatologist to get proper diagnosis. The sooner the better.