Your wife needs a diagnosis. The ones that come to mind are bullous impetigo, a staph infection, or bullous pemphigoid, an autoimmune skin disease. Neither is serious, and neither affects internal organs. Both need treatment, however, antibiotics in the first case and anti-inflammatory agents in the other. There are other possibilities too, but every one I can think of just affects the skin, not the innards.
To find out what this is and what to do, please have your wife see a skin doctor.
Best.
Dr. Rockoff