A 64-year-old woman presents to your dermatology office for the evaluation of a rash. The rash comes and disappears on her face and groin. She went to the urgent care center and was prescribed prednisone tablets for allergic dermatitis. She was started on metformin a month ago for diabetes. She lost 4 pounds in one month. Her current medications include metformin for diabetes, prednisone for skin rash, hydrochlorothiazide and metoprolol for hypertension. A review of systems reveals diarrhea and depressive thoughts. Her family history is significant for inherited endocrine disorders. On physical examination, you notice an erythematous rash with red plaques of annular shape with central blistering and bulla formation on her face and in the groin area. Her fingertips are red, shining, and erosive. Laboratory tests show serum glucagon elevated 15 times normal and an elevated glucose level. A CT scan of the abdomen demonstrated a mass in the tail of the pancreas. The characteristic rash on this patient caught your attention. What is the rash found in this disease?
