A 65-Year-Old Woman Is Brought to the Emergency Department by Paramedics

A 65-year-old woman is brought to the emergency department by paramedics after falling on a snow-covered sidewalk.  The patient fell backward onto her hands while trying to maintain her balance and immediately felt a sharp, excruciating pain in her right arm.  She also notes mild tenderness and bruising on the right flank and right buttock.  The patient has a history of osteoporosis and hypertension and takes valsartan, alendronate, and a vitamin D supplement.  She does not use tobacco, alcohol, or illicit drugs.  In the emergency department, radiograph reveals a displaced fracture of the right distal radius.  The patient is admitted to the hospital and undergoes open reduction and internal fixation of the radius fracture.  On postoperative day 2, she reports severe, constant, burning pain over her right flank.  The postsurgical pain in the right arm is mild and well controlled with low-dose morphine as needed.  Temperature is 37.8 C (100 F) , blood pressure is 145/84 mm Hg, pulse is 97/min, and respirations are 16/min.  Mucous membranes are moist and the oropharynx is without lesions.  Cardiopulmonary auscultation reveals clear lungs and normal heart sounds.  The abdomen is soft, nontender, and nondistended.  The right flank is tender to light touch with a rash over the area, as shown in the exhibit.  The surgical wound is healing normally without signs of infection.
What is the most appropriate treatment for this patient?

A) Intravenous acyclovir for 3 days
B) Morphine discontinuation and topical medium-potency corticosteroid cream
C) Oral acyclovir for 7 days and prednisone for 3 days
D) Oral valacyclovir for 7 days
E) Pain control and zinc oxide-based cream