Tropical pyomyosistis is an uncommon condition in the United Kingdom. Early diagnosis and appropriate treatment are crucial for a good outcome. We had seen 13 cases in our previously published series from 1998 to 2009. This is an update showing a significantly increased incidence from 2010 to 2016.

A retrospective review of all cases of pelvic pyomyositis in our centre from January 2010 to April 2016 was undertaken from case notes and radiology reports. All children with clinical and radiographic evidence of pyomyositis were included. Since our previous publication we had changed our practice to get an MRI scan in all children who presented with a limp, fever and raised inflammatory markers, and had no effusion in the hip ultrasound scan.

We identified 24 children with a mean age of 7 years (range, 1 week to 14 years). MSSA (Methicillin-Sensitive Staphylococcus aureus) was the most common cultured organism (n=8). Median hospital stay was 9 days (3 to 12). Obturator internus was the most common muscle affected. All patients had appropriate antibiotics with 2 patients requiring surgical drainage of abscesses. The majority of children (n=22) showed a complete recovery with antibiotics only.

Incidence of pyomyositis has increased dramatically in our population and early diagnosis can result in a good outcome. We recommend MRI scan in all patients who present with a clinical picture of septic arthritis of the hip but with no effusion.