1 - Hospital de Dona Estefânia, CHULC-EPE, Paediatrics, Lisbon, Portugal,
2 - Hospital de Dona Estefânia, CHULC-EPE, Paediatrics Orthopaedic Unit, Lisbon, Portugal
3 - Hospital de Dona Estefânia, CHULC-EPE, Radiology Department, Lisbon, Portugal
4 - Hospital de Dona Estefânia, CHULC-EPE, Paediatrics Infectious Diseases Unit, Lisbon, Portugal
- ESPID
Introduction and aims: Pyomyositis is a primary infection of the skeletal muscle, commonly affecting the lower limbs. It occurs by seeding in the muscle, during transient bacteraemia. Our aim was to describe pyomyositis’ epidemiology, diagnosis setting, treatment and outcome in Paediatric patients.
Methods: Retrospective, unicentric study of children and adolescents diagnosed with pyomyositis in a tertiary care Paediatric Hospital, from June 2008 to June 2022. Predisposing factors, clinical, laboratory and radiological results, treatment and evolution were analysed.
Results: 27 patients were identified, 74% male, median age of 8 years old [2;13]. The most common predisposing factors were trauma (33%) and intense physical activity (33%). Pain (100%), fever (63%) and limited range of movement (ROM) (59%) were the most frequent symptoms, with a median onset of 6 days [2;10] and 52% were diagnosed at the first Emergency Department visit. The lower limb was the most affected site (86%), specially the hip muscles (46%). All patients had altered inflammatory parameters (median CRP 98.8 mg/L; median ESR 40 mm/h). MRI had 100% sensitivity, whereas 40% of ultrasounds were inconclusive. Blood cultures were positive in 36%. MSSA was the most common organism isolated (28%), but in 60% patients no agent was identified. Most patients were treated with intravenous flucloxacillin plus clindamycin (52%) for a median 14 days [9;17] and median total duration of 28 days [19;39]. Drainage was performed in 6 patients. All patients improved without ROM limitation at 6-month follow-up.
Conclusions: Pyomyositis is difficult to diagnose, since symptoms can be nonspecific. Nevertheless, early diagnosis and treatment were essential. MSSA was the most isolated organism, as in other series, but in 60% no agent was identified, probably related to low drainage rate.
Palavras Chave: musculoskeletal infections, pyomyositis, Staphylococcus aureus