72-Year-Old Woman With Redness, Swelling, and Pain of the Forearms and Hands

Abstract

dent tious A 72-year-old woman from far eastern Kansas who had a history of psoriatic arthritis treated with methotrexate and infliximab presented to the Mayo Clinic Hospital, Saint Marys Campus emergency department for evaluation of redness, swelling, and pain of both forearms and hands of 10 weeks’ duration. Psoriatic arthritis had been diagnosed 4 years earlier, and her disease had been under good control until 3 months previously. Six weeks before the current presentation, the patient’s rheumatologist stopped her methotrexate, started prednisone at 20 mg/d (tapered to 2.5 mg/d), and increased the frequency of her infliximab infusions from every 6 weeks to every 4 weeks in the setting of worsening hand pain, swelling, and redness. Two weeks before presenting to the emergency department, redness, swelling, and induration of her forearms developed. Her right hand grew increasingly painful, and black skin discoloration developed over the right thumb pad. On presentation, her vital signs were notable for a heart rate of 116 beats/min and respirations of 25/min. Physical examination revealed diffuse edema of both forearms and hands with overlying erythematous, indurated plaques on the left forearm without palpable tenderness or crepitus. Marked swelling, induration, erythema, warmth, and scaling were noted on the thenar eminence and palmar metacarpophalangeal joint line of the right hand. There were 2 discrete areas of ulcerated black, dry, nonmalodorous skin on the right thumb pad. Laboratory studies yielded the following findings (reference ranges provided parenthetically): leukocytes, 10.5 10/L (3.5-10.5 10/L) with 54% neutrophils; plasma lactate, 3.3 mmol/L (0.6-2.3 mmol/L); and C-reactive protein, 128.2 mg/L ( 8.0 mg/L). Plain radiography of the hands revealed severe erosive osteoarthritis, chondrocalcinosis, and no subcutaneous gas.