Multiple blisters on the extremities

A 62-year-old white male complained of blisters on his arms, hands, knees, and feet for about 3 months; he denied lesions in his mouth or groin. Medical history was significant for well-controlled type 2 diabetes and hypertension.

There was no history of fatigue, fevers, arthralgias, diarrhea, or new medications. To the man’s knowledge, no one else in his family had any ...