FRI0533 Primary Pyomyositis in Children: A Retrospective Review of 25 Cases

Abstract

Background Primary pyomyositis is a rare condition in children that should be included in the differential diagnosis of musculoskeletal infections. Objectives To describe the clinical features of pyomyositis as well as its diagnostic and therapeutic approach. Methods A descriptive and retrospective study was performed by reviewing medical records of patients admitted to our hospital from January 1996 to July 2013 with a diagnosis of primary pyomyositis. Results A total of 25 patients (16 men, 9 women) aged between one month and 14 years (median age 2 years) were registered. Two peaks of incidence have been found in the months of July and October. The most frequent clinical manifestations were the presence of local pain (24 patients), fever (18 patients), local swelling (9 patients) and skin rash (7 patients). Predisposing factors in 8 patients (1 strenuous exercise, 4 trauma, 3 intramuscular injections) were found. The primary site was pelvic muscles or lower extremities (20 patients). In laboratory results, we found the presence of leukocytosis, with an average value of 12,936±5.753/uL leukocytes, total neutrophils 4.659/uL ±7.350), ESR of 55±28 mm) and PCR 8±6 mg/dL). CPK was normal in 5 out of 6 patients who were requested. Laboratory results were positive for Staphylococcus aureus (7 patients), Salmonella no tiphy (1 patient) and Bacteroides fragillis (1 patient). Ultrasound suggested the diagnosis in 11 cases and magnetic resonance imaging support the diagnosis in all cases. All patients received intravenous antibiotic therapy (mean duration 11 days) followed by oral antibiotic therapy (mean duration 23 days). 9 patients suffered complications as abscess formation, 3 need abscess aspiration and one of them required surgical drainage. None of our patients had residual functional limitations. Conclusions It is important to have a high index of suspicion for pyomyositis in patients with fever and musculoskeletal pain at an early stage in order to initiate start appropriate antibiotic treatment against Staphylococcus aureus. Although ESR and ultrasound may be useful, it is necessary to complement with magnetic resonance imaging in order to support the diagnosis in all cases. Disclosure of Interest None declared DOI 10.1136/annrheumdis-2014-eular.4467

Factors associated with pyomyositis: A systematic review and meta‐analysis

“…Twenty-five papers were included in the narrative synthesis: twenty-two case series, one case control, one cohort and one cross-sectional study [9][10][11][12][13][14][15][16][17][18]21,25,26,28,[44][45][46][47][48][49][50][51][52][53][54].…”

“…The articles were published between 1979 and 2020 with over 40% in the last decade. Five studies only included children [18,28,46,47,51]. The studies were conducted across six continents in countries with income levels that were high ( 13 [12,13,18,26,28], anaemia [9,17,21,48], malnutrition [45,48,49], skin infection [12,13,28], injecting drug use [12,14,17,45,52], cancer or malignancy [11,12,17,45,53,54], malaria [26,48], urinary tract or renal infection [17,26,52,53], liver cirrhosis [11,17,52,53], intramuscular injection [18,51], autoimmune disease [11,14], and immunosuppressive medication [9,…”

“…AIDS), diabetes mellitus, leukaemia, cancer or malignancy, renal failures, and autoimmune diseases [9][10][11][12]. Pyomyositis has been related to insults that affect skeletal muscle, such as rigorous physical exercise, trauma, injecting drug use, intramuscular injection and underlying viral or parasitic myositis [13][14][15][16][17][18][19].…”

“…Early detection is considered as the most effective intervention in minimizing the complications of the disease. Most of the studies about pyomyositis have been hospital-based case reports and case series [9,[11][12][13][14][16][17][18][26][27][28], with few observational analytical studies; however, the findings vary from one country to another [29][30][31][32][33][34]. Although recent review articles have been published, no meta-analysis has been conducted [2,35,36].…”

“…Males aged less than 20 years predominated. The principal organism isolated in pyomyositis was Staphylococcus aureus, identified in around 30% to more than 90% cases where culture results were reported[9][10][11][12][13][14][15][16][17][18]21,25,26,28,[44][45][46][47][48][50][51][52]54 ]. Potential predisposing factors related to pyomyositis were trauma[10,12,[15][16][17][18]21,25,26,28,44,46,49,50,53,54], diabetes mellitus[9][10][11][12]14,16,17,25,26,44,…”