Case Report
A 6-year-old previously healthy female presented with a history of right wrist swelling and pain. Her symptoms began 2 days prior to presentation shortly after someone stepped on her wrist. After the initial incident, she felt moderate pain. The following day, the pain worsened, and she developed redness and swelling of the joint with a subjective fever.
On physical exam in the emergency department, the patient was febrile at 39.4°C and tachycardic with a heart rate of 140 bpm. Her wrist was swollen, erythematous, and tender to palpation. Exquisite pain was elicited by motion, and there was limited range of motion of the joint. Laboratory studies revealed elevated erythrocyte sedimentation rate (ESR) at 40 mm/h and C-reactive protein (CRP) at 13.5 mg/dL, and blood cultures were drawn.
Orthopedic Surgery was urgently consulted and performed a joint aspiration in the emergency department, extracting frankly purulent fluid from the joint. Gram stain of the fluid demonstrated gram-positive cocci with numerous neutrophils, and the fluid was sent for culture. She was admitted to the hospital, and treatment with intravenous (IV) clindamycin was begun.
Hospital Course
The following day, Orthopedic Surgery performed an arthrotomy in the operating room. On incision of the joint capsule, seropurulent fluid was expressed, and the joint space was copiously irrigated. She continued to receive IV clindamycin after surgery.
On the first postoperative day, repeat ESR was 85 mm/h, and CRP was 11 mg/dL. She was afebrile, and her pain was well controlled by acetaminophen. Within 48 hours of admission, the joint aspiration fluid culture was positive for Streptococcus pyogenes, and within 72 hours, the blood culture was positive for Streptococcus pyogenes. Infectious Disease was consulted, and the antibiotic regimen was switched from IV clindamycin to IV cefazolin.
On the third postoperative day, Orthopedic Surgery performed a repeat arthrotomy for reassessment of the joint. On entry into the joint capsule, there was no return of fluid, and the joint was irrigated and closed. The patient continued to receive IV cefazolin. Serial ESR and CRP levels trended downward. A repeat blood culture performed 2 days after admission showed no growth after 48 hours. The patient was discharged on the sixth day of admission with a 3-week course of oral cephalexin. On outpatient follow-up with Infectious Disease, her ESR and CRP normalized with completion of the oral antibiotic course.
Final Diagnosis
Group A streptococcal bacteremia and septic joint
Discussion
Staphylococcus aureus is the most common pathogenic organism causing acute septic arthritis in children. Recent research reveals a changing pattern in the etiology, with the emergence of methicillin-resistant S aureus (MRSA) as a commonly identified causative organism. A systematic review of 158 pediatric patients diagnosed with acute osteoarticular infection at an established medical center revealed an increase from 4% to 40% in cases caused by MRSA from years 2000 to 2004. The growing prevalence of MRSA septic arthritis is significant considering the associated increased morbidity, including longer hospital stays, increased occurrence of subperiosteal abscess, and more frequent surgical treatment.1 Although we cannot disregard the importance of a heightened awareness of MRSA as a cause for septic arthritis, our case proves that we must still consider other etiologies, including group A streptococcus (GAS).
Invasive GAS infections involve GAS isolation from a normally sterile site and include bacteremia, pneumonia, necrotizing fasciitis, osteomyelitis, and septic arthritis. A review of 12 cases of children with invasive GAS infection admitted to the intensive care unit demonstrated the potential severity and significant morbidity of invasive infection. Of the 12 cases, 9 patients had multiorgan failure, 9 required inotropic and/or vasopressor support, 10 required mechanical ventilation of a median of 8 days, and 4 required extrecorporeal membrane oxygenation support.2 A case report of a 5-year-old male presenting with septic knee arthritis describes the progression of the disease to streptococcal toxic shock syndrome. The authors emphasized the importance of prompt orthopedic surgical evaluation and management to minimize the possible morbidity and mortality.3 In our case, the orthopedic surgery team was consulted on presentation in the emergency department and performed surgical debridement of the joint in the same night. The surgical team repeated incision and irrigation of the joint several days later to ensure that there were no residual signs of infection. With close surgical follow-up and intravenous antibiotics, our patient recovered within a week with no significant complications.
Conclusion
Given the increasing prevalence and the associated increased morbidity, it is important that we maintain a strong suspicion for MRSA as a cause for septic arthritis. It is also important that we consider other infectious causes, like GAS, which is associated with severe morbidity and toxic shock syndrome. Surgical evaluation and prompt antibiotic therapy is important regardless of etiology. Fortunately our patient’s clinical course was benign with no morbidity following prompt surgical management and intravenous antibiotics.
Footnotes
Author Contributions: As the primary author, AA obtained the patient information and relevant research and drafted the original manuscript. Both CW and NS critically revised the manuscript and gave final approval.
Declaration of Conflicting Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding: The author(s) received no financial support for the research, authorship, and/or publication of this article.
References
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