Pitfalls in diagnosing septic arthritis in Hong Kong children: ten years' experience

To evaluate the initial presentation of septic arthritis in Hong Kong children with respect to clinical and laboratory findings that can aid making a prompt diagnosis.

Retrospective review.

Five public hospitals in Hong Kong.

Data concerning paediatric patients with septic arthritis were collected from January 2001 to December 2010. Patients with postoperative infections and those without enough retrievable information were excluded.

Of 31 patients analysed, on admission only 52% had had a fever of <38.5°C and 71% had raised white blood cell count of <12 x 10(9) /L. In 74% of these patients, Gram stains of blood culture samples yielded no positive findings. The leading causative organism was Staphylococcus aureus (42%), followed by group A Streptococcus (23%). When group A Streptococcus was responsible, five out of seven patients had a complicated clinical course (repeated surgeries, Streptococcus-related organ failure, and chronic joint stiffness). Moreover, in 19% of instances, the empirical antibiotic therapy prescribed on admission did not provide a broad enough spectrum of cover.

Signs of sepsis such as high fever, raised white blood cell count, and positive Gram smear from blood cultures were only present in around half of these patients with septic arthritis. Furthermore, group A Streptococcus tended to produce many complications. Regrettably, about a quarter of the empirical antibiotic regimens started by frontline staff were deemed not have a broad enough spectrum of cover. Improvement in the initial detection and management of septic arthritis patients is warranted.