Pruritic Blisters Over Trunk and Extremities; Acute Onset of Fever, Malaise, and Rash

An 82-year-old woman notes acute onset of tense blisters at a trauma site on her left knee. A 78-year-old white man presents to the urgent care center with acute onset of fever, malaise, and a rash, which he notes developed approximately 7 days after starting macrolide antibiotic therapy.