A patient is being treated in an outpatient wound center for an infected plantar diabetic foot ulcer. Treatment includes debridement as needed, silver sulfadiazine, dry dressings, and offloading with a post-op shoe. On the second day of treatment, the patient reports a rash and severe pruritus around the wound and along the dorsum of the foot. The most likely cause of the patient's symptoms is

a(n):

A. maceration due to improperly managed exudate.
B. rapidly progressing wound infection.
C. untreated Charcot foot.
D. cutaneous drug reaction to silver sulfadiazine.

D