A 63-year-old man comes to the physician because of a 2-day history of a painful rash on his right flank. Two years ago, he underwent cadaveric renal transplantation. Current medications include tacrolimus, mycophenolate mofetil, and prednisone. Examination shows an erythematous rash with grouped vesicles in a band-like distribution over the patient's right flank. He is diagnosed with an acute shingles and given an appropriate treatment. On follow up after 4 weeks, he reports persistent burning and stabbing pain in the same region that has now become severe. he is started on topical capsaicin cream, and his pain improves markedly over the next several days. Decreased activity of which of the following neurotransmitters is most likely associated with pain relief in this patient?

Question

A 63-year-old man comes to the physician because of a 2-day history of a painful rash on his right flank. Two years ago, he underwent cadaveric renal transplantation. Current medications include tacrolimus, mycophenolate mofetil, and prednisone. Examination shows an erythematous rash with grouped vesicles in a band-like distribution over the patient's right flank. He is diagnosed with an acute shingles and given an appropriate treatment. On follow up after 4 weeks, he reports persistent burning and stabbing pain in the same region that has now become severe. he is started on topical capsaicin cream, and his pain improves markedly over the next several days.  Decreased activity of which of the following neurotransmitters is most likely associated with pain relief in this patient?

Quizplus · Accepted Answer

Eductional Objective: Topical capsaicin causes defunctionalization of afferent pain fibers and depletion of substance P.  Initial application results in a burning and stinging sensation, but chronic exposure leads to reduced pain transmission.

A 63-Year-Old Man Comes to the Physician Because of a 2-Day