A 62-year-old man with end-stage renal disease presented to our dermatology clinic with 2-month-old ulcerations on his distal left ring finger. He was on hemodialysis and had a radiocephalic arteriovenous fistula (AVF) on his left arm. He had been empirically treated elsewhere with oral trimethoprim-sulfamethoxazole for a presumed bacterial infection, without improvement. He was then treated for contact dermatitis with topical clobetasol, which led to ulcer expansion and worsening pain.
At our clinic, the patient reported intermittent pain in his finger and paresthesias during activity and dialysis, but no tenderness of the ulcers. He had atrophy of the intrinsic left hand muscles (his non-dominant hand) with associated weakness. Three weeks earlier, he’d received a blood transfusion for anemia. Afterward, the pain in his hand improved and the ulcers decreased in size.
On exam, the AVF had a palpable thrill over the left forearm. The radial pulses were palpable bilaterally (2+) and the left ulnar artery was palpable, but diminished (1+). The patient’s left hand was cooler than the right (with a slight cyanotic hue and visible intrinsic muscle atrophy) and had decreased sensation to pain and temperature. Four ulcers with dry yellow eschar were located over the dorsal interphalangeal joints (FIGURES 1A AND 1B). They were essentially non-tender, but there was tenderness in the adjacent intact skin. There was violaceous blue edematous congestion noted on the fourth finger, and the distal phalange was constricted, giving it a “pseudoainhum” appearance.
