Shorter antimicrobial courses may sufficiently treat childhood septic arthritis

A 10-day course of high dose oral antibiotics following initial parenteral administration was just as effective at treating childhood septic arthritis as the commonly accepted 30-day treatment course, data from a recently published study indicated.

Heikki Peltola, MD, and other researchers from Helsinki enrolled 154 children aged 3 months to 15 years who had septic arthritis and were admitted to one of seven Finnish hospitals between 1983 and 2005. The cohort (n=130) was assigned to either a 10-day treatment group (n=63) or a 30-day treatment group.

The researchers noted most of the cases were caused by Staphylococcus aureus, Streptococcus pyogenes or Haemophilus influenzae.

Patients received either clindamycin (40 mg/kg per day every six hours) or a first-generation cephalosporin (150 mg/kg per day every six hours), following initial IV treatment for the first two to four days after diagnosis. Ampicillin or amoxicillin (200 mg/kg per day every six hours) was prescribed for children with Haemophilus influenzae type b infections.

Surgical procedures were performed as follows:

One-hundred and ten patients received percutaneous aspiration, with seven receiving needle lavage.
One patient underwent knee arthroscopy.
Fifteen patients had arthrotomy with occasional drilling to the adjacent bone.

Children who underwent surgical procedures experienced slower decreases in serum C-reactive protein levels and erythrocyte sedimentation rates compared with those who did not. The researchers attribute these differences to inflammatory reactions provoked by surgical intervention.

Patients who experienced improvements in fever and local symptoms, and whose CRP levels decreased to less than 20 mg/L were taken off of antibiotics regardless of ESR. Follow-up visits were conducted at two weeks, three months and one year following hospitalization.

Peltola and colleagues concluded that larger doses of the antimicrobials for less than two weeks and only one joint aspiration were sufficient for most cases, regardless of the infecting pathogen, “if the clinical response is good and the C-reactive protein level normalizes shortly after initiation of treatment.”

In an accompanying editorial, John S. Bradley, MD, of the division of infectious diseases at Rady Children’s Hospital, San Diego, noted that it may not be in the patient’s best interest to pursue a shortened course of treatment “for physicians who cannot follow up with children closely as outpatients.” However, he said this data can pave the way for “a larger, prospective well-controlled comparative study can to assess whether 10 days of therapy is truly noninferior to 30 days of therapy.”

Peltola H. Clin Infec Dis. 2009;doi:10.1086/597582.

Bradley JS. Clin Infec Dis. 2009;doi:10.1086/59783.