A few days after an incidental cat bite, a patient presented to the emergency department for treatment of poison sumac exposure. He was discharged with oral methylprednisolone for the dermatitis and returned 1 week later with symptoms, examination findings, and laboratory results consistent with sepsis and bilateral upper extremity necrotizing soft-tissue infections. After administering multiple irrigation and débridement procedures, hyperbaric oxygen treatments, and an antibiotic regimen, the patient’s status greatly improved. However, the patient returned 1 month later with a new sternoclavicular joint prominence that was associated with painful crepitus. Additionally, he noted that his wrists were gradually becoming more swollen and painful. Imaging studies showed a lytic destruction of the sternoclavicular joint and erosive changes throughout the carpus and radiocarpal joint bilaterally, consistent with osteomyelitis. The patient was treated with ertapenem for 6 weeks, and his polyarthropathy resolved. The patient provided written informed consent for print and electronic publication of this case report.
Case Report
A 73-year-old, right-hand–dominant man with no notable medical history presented to the emergency department for treatment of poison sumac exposure, incidentally, a few days after being bitten by a cat on the bilateral distal upper extremities. He was prescribed a course of oral methylprednisolone for dermatitis. A week later, the patient returned to the emergency department with altered mental status, fevers, diaphoresis, lethargy, and polyarthralgia. At the time of presentation, the patient’s vital signs were labile, and he was found to have extensive bilateral upper extremity erythema, blistering, petechiae, purpuric lesions, and exquisite pain with passive range of motion of his fingers and wrists. His leukocyte count was 25.1 × 109/L, and he had elevated C-reactive protein level and erythrocyte sedimentation rate of 150 mg/L and 120 mm/h, respectively. He was admitted for management of sepsis and presumed bilateral upper extremity necrotizing soft-tissue infection.
Broad-spectrum intravenous (IV) antibiotics (vancomycin, piperacillin, tazobactam) were initiated after blood cultures were obtained, and the patient was taken emergently to the operating theatre for irrigation and débridement of his hands and wrists bilaterally. Arthrotomy of the wrist and débridement of the distal extensor compartment and its tenosynovium were performed on the right forearm, in addition to a decompressive fasciotomy of the left forearm. Postoperatively, the patient’s mental status improved and his vital signs gradually normalized. He received multiple hyperbaric oxygen treatments and underwent several additional operative débridement procedures with eventual closure of his wounds. At initial presentation, the differential diagnosis for the severe soft-tissue infection included necrotizing fasciitis or myositis caused by any of a variety of bacterial pathogens. Most notably, it was important to elicit the history of a cat bite to include and consider Pasteurella multocida as a potential pathogen. Initial cultures supported the diagnosis of acute P multocida necrotizing skin and soft-tissue infection, in addition to septic arthritis. The patient’s blood and intraoperative wound cultures grew P multocida. The antibiotic treatment was tailored initially to ampicillin and sulbactam and then to a final regimen of orally administered ciprofloxacin (750 mg twice a day), once susceptibility testing was performed on the cultures. On hospital day 10, the patient was discharged home, receiving a 6-week course of ciprofloxacin to complete the 8-week course of treatment.
At follow-up, approximately 1 month after discharge, the patient noted that he had developed a new right sternoclavicular joint prominence that was associated with painful crepitus. He also noted that his wrists were gradually becoming more swollen and painful bilaterally. Computed tomography scans of the chest were obtained to evaluate the sternoclavicular joint (Figure 1). Repeat radiographs of the wrists were also obtained (Figure 2). Imaging showed lytic destruction of the sternoclavicular joint and erosive changes throughout the carpus and radiocarpal joint, consistent with osteomyelitis. The C-reactive protein level and erythrocyte sedimentation rate at this time were 34 mg/L and 124 mm/h, respectively.
The patient returned to the operating room for débridement and biopsy of the right sternoclavicular joint and left wrist. This patient’s delayed presentation was characterized by a subacute worsening of isolated musculoskeletal complaints. The differential diagnosis then included infection with the same bacterial pathogen versus reactive or inflammatory arthritis. Several intraoperative cultures failed to grow any bacteria, including P multocida, although P multocida was the presumptive cause of the erosive polyarthropathy, considering that symptoms eventually resolved with a repeated course of IV-administered ertapenem for 6 weeks. The patient experienced complete resolution of his joint pain and swelling. He was able to resume his activities of daily living and had no further recurrence of symptoms at follow-up 3 months later.