Treatment of Septic Arthritis in Children
Abstract & Commentary
By Hal B. Jenson, MD, FAAP, Professor of Pediatrics, Tufts University School of Medicine, and Chief Academic Officer, Baystate Medical Center, Springfield, MA, is Associate Editor for Infectious Disease Alert.
Dr. Jenson is a speaker for Merck.
Synopsis: A randomized study of treatment of septic arthritis in children 3 months to 15 years of age demonstrated that 10 days of treatment, with an initial 2-4 days intravenously followed by oral therapy, was sufficient for most cases, regardless of the infecting pathogen or site of infection.
Source: Peltola H, et al. Prospective, randomized trial of 10 days versus 30 days of antimicrobial treatment, including a short-term course of parental therapy, for childhood arthritis. Clin Infect Dis. 2009;48:1201-1210.
A randomized, multicenter, open-label, parallel group, noninferiority trial of childhood septic arthritis was performed at seven referral hospitals in Finland from 1983-2005. The study included children 3 months to 15 years of age with acute septic arthritis, diagnosed by fever painful and swollen joint (without history of trauma), restriction of motion, and tenderness and warmth often. Cases with concomitant osteomyelitis were excluded.
Patients received either clindamycin (40 mg/kg/day every six hrs.) or a first-generation cephalosporin (cephradine, cephalexin, or cephadroxil (150 mg/kg/day divided every six hrs.), and were randomized by birthday (odd or even) to receive treatment for 10 or 30 days. Prior to the vaccination and elimination of Haemophilus influenzae-type B infections in Scandinavia in 1997, ampicillin or amoxicillin was also administered to children 0-4 yrs. of age until the causative agent was identified. Antimicrobial treatment was initiated intravenously for 2-4 days, with the treatment course completed by oral administration at the same doses. Non-steroidal anti-inflammatory agents were administered as needed.
Septic arthritis was diagnosed in 200 children; 130 had a positive culture and were evaluated, including 63 (48%) who received 10 days and 67 (52%) who received 30 days of treatment. The mean age was 6.5 years (median, 5.7 years). Medical attention was sought by 85 patients (65%) within three days and by 121 patients (93%) within six days. The sites included the hip in 48 patients (37%), the knee in 32 (25%), and the ankle (tibiotalar joint) in 30 (23%). There were no significant differences in distribution among the groups.
The initial mean CRP was slightly higher in the 10-day treatment group compared to the 30-day treatment group (93 mg/L vs. 83 mg/L, respectively), and the mean ESR was similar between the two groups (54 mm/hr vs. 56 mm/hr, respectively). Percutaneous aspiration was performed in 110 patients, arthrotomy in 15 patients, and knee arthroscopy in one patient. Four patients did not have a surgical procedure.
Blood and synovial fluid cultures were positive in 41 patients (32%), blood only in 29 (22%), and synovial fluid only in 60 (46%). Staphylococcus aureus (all methicillin-susceptible) was the most common cause, and cultured from 76 patients, H. influenzae type B in 23 cases, Streptococcus pyogenes in 16 cases, Streptococcus pneumoniae in 11 patients, Neisseria meningitidis in two cases, and one case each of Streptococcus group G and viridians Streptococcus.
Most patients recovered quickly, with no significant differences between groups. At the three-month follow-up, three patients had minor joint symptoms, each of which resolved by one year. One 10-year-old boy had two late recurrences of S. aureus infection in the same joint. No other patient had relapse, recrudescence, residual dysfunction, growth disturbance, or other clinical sequelae.
Commentary
The current recommendations for treatment of childhood arthritis date back to clinical studies performed almost 40 years ago. A significant change occurred just over 30 years ago when oral therapy, following an initial short course of intravenous therapy, was shown to be as effective as prolonged intravenous therapy. Since that time, however, the standard total duration of treatment continues to be recommended as a total of three weeks.
Shorter duration of therapy for septic arthritis has been advocated by some, including clinicians in Scandinavia, to minimize the unnecessary use and adverse effects of antimicrobial therapy. This non-inferiority study provides the proof of concept that 10 days of treatment for septic arthritis, with a short course of intravenous therapy initially, and using standard medications, is generally as effective as a 30-day treatment. Many of the other important aspects of treatment, such as clarifying the optimal antimicrobial and role of surgery, could not be studied, even during this well-controlled study that was conducted over a 22-year period.
The environment has changed significantly over the course of this study. H. influenzae type B, once a common cause of joint infections in children less than four years of age, is now a rare cause of joint infections among immunized children. No cases in this study were caused by methicillin-resistant S. aureus, which is increasingly common but usually susceptible to clindamycin.
Children with septic arthritis are candidates for less than three weeks of therapy if the infection is uncomplicated, does not involve the hip, caused by methicillin-susceptible S. aureus or Streptococcus, shows a good clinical response to therapy with normalization of the CRP by 10-14 days, and there is assurance of good adherence to follow-up. Children with one or more complicating factors should continue to receive treatment following the customary recommendation for at least three weeks of therapy. Further studies are needed to validate a possible recommendation for 10 days as standard duration of therapy.
Childhood septic arthritis is different from joint infections among adults. The bone and joint microvasculature among younger patients has greater vascular flow and ostensibly better perfusion and distribution of antibiotic to the infected site, with less risk for sequestered infection. The higher doses of oral antibiotics used for bone and joint infections in children that were used in this study, and the even higher doses recommended in other treatment guidelines for septic arthritis in children, are generally well tolerated but may be problematic to replicate among adults on a per kg dosing basis. A comparable study of oral treatment of septic arthritis among adults is necessary to document safety and efficacy of these regimens.
A randomized, multicenter, open-label, parallel group, noninferiority trial of childhood septic arthritis was performed at seven referral hospitals in Finland from 1983-2005.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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