Prednisone60mg/5days, & promethazine25mg for bullous pemphigoid. med has caused rash popping up all over, even hands/feet. how to treat? ( see pics).

Risky: The rash can be any number of things from infection of the original blistering rash to adverse effect of taking a new medication. Some adverse drug reactions are life threatening if not identified early. It is possible to review a photograph via virtual consult and to ask a few key questions to put you in the right direction, but ultimately, you need to be examined in the near future.

See a dermatologist: Promethazine (phenergan) is of no use for bullous pemphigoid and will do nothing except sedate you. "Rash popping up all over" is too vague a description for any opinion. BP is very serious. How was the diagnosis established? Have you been exposed to other meds? You need immediate attention not available on line. Be sure the DR understands it is URGENT when you call.