Clinical Characteristics and Management of Children and Adolescents Hospitalized With Pyomyositis.

BACKGROUND: Pyomyositis, a bacterial muscle infection, is an important differential diagnosis in children and adolescents with musculoskeletal pain. In contrast to tropical regions, it is rarely recognized in temperate countries, but incidence is increasing and major studies are missing. METHODS: This retrospective multicenter study included patients <18 years of age hospitalized with pyomyositis in 11 Swiss children's hospitals between January 2010 and December 2022. Cases were identified by ICD-10 code (Myositis; M60-M60.9), and data was extracted from electronic hospital records. RESULTS: Of 331 patients identified, 102 fulfilled the case definition. Patient age at presentation ranged from 2 weeks to 17 years (median 8 years). The majority had no underlying illness and all presented with fever and localized pain. At the respective site of pyomyositis, 100 (98%) had impaired movement and 39 (38%) presented with local swelling. Pelvic (57%) and leg (28%) muscles were mostly affected. Blood or tissue cultures were obtained in 94 (92%) and 59 (57%) patients, respectively. Of those, 55 (58%) blood and 52 (88%) tissue cultures were positive, mainly for Staphylococcus aureus (35 and 19, respectively) and Streptococcus pyogene s (12 and 15, respectively). All patients received antibiotic treatment during hospitalization for a median of 10 days (interquartile range: 7-17), followed by outpatient treatment for a further median of 16 days (interquartile range: 11-22) in 95 (93%) patients. Fifty-nine (57%) patients required surgery. CONCLUSIONS: Pyomyositis is a challenging diagnosis that requires a high level of awareness. Blood and/or tissue cultures revealed S. aureus and S. pyogenes as the predominant causative agents.

Piomiositis multifocal por Staphylococcus aureus: a propósito de un caso pediátrico / Multifocal pyomyositis due to Staphylococcus aureus: a clinical case study / Piomiosite multifocal por Staphylococcus aureus: relato de caso

Introducción: la piomiositis (PMS) es una infección bacteriana aguda o subaguda del músculo esquelético. Entidad rara en pediatría, suele acompañarse de la formación de abscesos. Se presenta más frecuentemente en preescolares de sexo masculino, afectando mayoritariamente a extremidades y región pélvica. La manifestación multifocal es frecuente. El principal agente etiológico es Staphylococcus aureus. Caso clínico: 3 años, sexo masculino, sano. Consulta por fiebre continua de hasta 39 ºC de seis días de evolución, dolor de ambos miembros inferiores a predominio izquierdo, cojera y repercusión general. Examen físico: tumoración en muslo izquierdo de límites difusos de 13 x 5 cm, lisa, firme, impresiona adherida a planos musculares, dolorosa. Sin elementos fluxivos en la piel. Ecografía de partes blandas: aumento de tejidos blandos de la extremidad. Resonancia magnética (RM): abscesos que comprometen logia de los aductores del miembro izquierdo, el vasto externo del muslo derecho, musculatura paravertebral lumbar izquierda y cérvico-torácica izquierda. Tratamiento: drenaje, requiere de múltiples limpiezas quirúrgicas y antibioticoterapia prolongada. Cultivo de la lesión: Staphylococcus aureus meticilino resistente (SAMR). Buena evolución clínica e imagenológica. Discusión: la PMS ha presentado una incidencia creciente con la aparición del SAMR. La ecografía es un método adecuado para realizar diagnóstico local. La experiencia en la interpretación de la RM permite pesquisar el compromiso multifocal, identificando focos sin traducción clínica. La antibioticoterapia y el drenaje quirúrgico son los pilares del tratamiento. El pronóstico es bueno en la mayoría de los casos.

Introduction: pyomyositis (PMS) is an acute or subacute bacterial infection of the skeletal muscle. It is a rare infection in pediatrics, and it is usually accompanied by abscess formation. It occurs more frequently in male preschoolers, mostly affecting the extremities and pelvic region. The multifocal manifestation is frequent. The main etiological agent is Staphylococcus aureus. Clinical case: 3 year-old, male, healthy patient. He consulted for continuous fever of up to 39ºC of 6 days of evolution, pain in both lower limbs predominantly on the left, lameness and general repercussions. Physical examination: a 13 x 5 cm tumor in the left thigh with diffuse limits, smooth, firm, adhered to muscle layers, painful. Without fluxive elements on the skin. Soft tissue ultrasound: enlargement of the soft tissues of the extremity. Magnetic resonance imaging (MRI): abscesses involving the adductor lodge of the left limb, the vastus lateralis of the right thigh, left lumbar paravertebral musculature and left cervical-thoracic musculature. Treatment: drainage, requires multiple surgical cleanings and prolonged antibiotic therapy. Culture of the lesion: methicillin-resistant Staphylococcus Aureus (MRSA). Good clinical and imaging evolution. Discussion: PMS has had an increasing incidence with the appearance of MRSA. Ultrasound is a suitable method for local diagnosis. Experience in the interpretation of MRI has enabled us to research multifocal involvement, identifying unobserved foci during clinical check-up. Antibiotic therapy and surgical drainage are the main treatments. The prognosis is good in most cases.

Introdução: Ia Piomiosite (TPM) é uma infecção bacteriana aguda ou subaguda do músculo esquelético. É uma entidade rara em pediatria, costuma vir acompanhada de formação de abscessos. Ocorre com maior frequência em pré-escolares do sexo masculino, afetando principalmente as extremidades e a região pélvica. A manifestação multifocal é comum. O principal agente etiológico é o Staphylococcus aureus. Caso clínico: paciente 3 anos, sexo masculino, hígido. Consulta por febre contínua de até 39ºC há 6 dias, dor em ambos os membros inferiores predominantemente esquerdo, claudicação e repercussão geral. Exame físico: tumor na coxa esquerda com limites difusos de 13 x 5 cm, liso, firme, aparentemente aderido aos planos musculares, doloroso. Sem elementos fluidos na pele. Ultrassonografia de tecidos moles: aumento dos tecidos moles da extremidade. Ressonância magnética (RM): abscessos envolvendo o alojamento adutor do membro esquerdo, vasto lateral da coxa direita, músculos paravertebrais lombares esquerdos e cérvico-torácicos esquerdos. Tratamento: drenagem, requer múltiplas limpezas cirúrgicas e antibioticoterapia prolongada. Cultura da lesão: Staphylococcus aureus resistente à meticilina (MRSA). Boa evolução clínica e imagiológica. Discussão: a TPM tem tido uma incidência crescente com o aparecimento do MRSA. A ultrassonografia é um método adequado para diagnóstico local. A experiência na interpretação de ressonância magnética permite-nos investigar o envolvimento multifocal, identificando focos sem tradução clínica. A antibioticoterapia e a drenagem cirúrgica são os pilares do tratamento. O prognóstico é bom na maioria dos casos.

Acute musculoskeletal infection in children: assessment and management.

Musculoskeletal infection in children is challenging to treat, and includes septic arthritis, deep tissue infection, osteomyelitis, discitis and pyomyositis. Delays to diagnosis and management, and under-treatment can be life-threatening and result in chronic disability. The British Orthopaedic Association Standards for Trauma include critical steps in the timely diagnosis and management of acute musculoskeletal infection in children, the principles of acute clinical care and the service delivery requirements to appropriately manage this cohort of patients. Orthopaedic and paediatric services are likely to encounter cases of acute musculoskeletal infection in children and thus an awareness and thorough understanding of the British Orthopaedic Association Standards for Trauma guidelines is essential. This article reviews these guidelines and associated published evidence for the management of children with acute musculoskeletal infection.

Pediatric musculoskeletal infections.

PURPOSE OF REVIEW: The aim of this article is to review the recent guidelines and literature regarding the diagnosis and the treatment of common pediatric musculoskeletal infections: septic arthritis, osteomyelitis, pyomyositis, and Lyme disease. RECENT FINDINGS: In the last decade, a better understanding of the causative organisms of common bacterial infections, including Kingella , leads to prompt targeted antimicrobial coverage in all musculoskeletal infections. Prompt diagnosis and treatment continues to be the mainstay in the treatment of children with osteoarticular infections. Efforts to improve early detection have lead to improving rapid lab diagnostic testing; however, more advanced diagnostics such as arthrocentesis for septic arthritis and MRI for osteomyelitis and pyomyositis, remain the gold standard. Shorter and narrowed antibiotic courses, with appropriate transition to outpatient oral treatment provide effective infection clearance and reduction in complications of disease. SUMMARY: Advances in diagnostics, including pathogen identification as well as imaging continues to improve our ability to diagnose and treat these infections, although still lack ability to provide definitive diagnosis without more invasive nor advanced techniques.

Meticillin-susceptible Staphylococcus aureus pyomyositis and cellulitis in right thigh of a 15-year-old boy: a case study.

Pyomyositis is a purulent infection of striated muscle and postoperative management remains the mainstay. If delayed primary wound closure is not managed in a timely manner, it often results in recurrent infection and sinus tract creation. Cavity wounds with sinus formation are known to complicate treatment, are problematic to manage and persist for long periods of time. The aim of this case report is to present the challenges in the assessment and management of a sinus tract with deep cavity wound, between the vastus lateralis and biceps femoris muscles, originating from liquefaction of a haematoma. Our review of the literature revealed limited research evidence in the management of deep cavity wounds. This is a rare case where the sinus tract route which leads to the rim-shaped cavity is embedded deep between the muscles, posing a high risk of recurrent infection from the premature closure of the wound tract. Successful management was attributed to: the accuracy in the initial wound assessment; appropriate dressing plans; the rationale for each action; and an outcome goal as each treatment progressed. Daily dressing change and reassessment of the wound was required to ensure progress and to address any complications in a timely manner. Finally, concerns of the patient and their family and regular discussions on the treatment plans are important to encourage adherence with management goals.

A case report: septic shock due to (tropical) pyomyositis and multiple metastatic embolisms caused by Panton Valentine Leukocidin-positive methicillin-sensitive staphylococcus aureus in a 12-year-old boy.

CASE REPORT: A 12-year-old boy, of Congolese roots and without medical history, first presented to our Emergency Department 3 days after blunt trauma of the left ankle. The boy represented on two more occasions in the next 3 days due to ongoing pain. On the last occasion he presented with severe hypoglycaemia. He was diagnosed with severe septic shock, secondary to subperiosteal abscess formation / osteomyelitis of the ankle. The patient was transferred to the paediatric intensive care unit where appropriate medical care was provided, including broad-spectrum antibiotic therapy, high dose vasopressor / inotropic support, surgical debridement of abscesses and below-knee amputation. PANTON VALENTINE LEUKOCIDIN TOXIN AND PYOMYOSITIS TROPICALIS: The causative organism was a methicillin-susceptible S. aureus, which upon further identification was a carrier of the PVL (Panton Valentine leukocidin) toxin. This pathogen is responsible for severe musculoskeletal infections. In children these infections are often associated with more severe clinical course requiring a higher need for surgical intervention and longer hospital stay.Tropical pyomyositis is a disease caused by Staphylococcus aureus, often seen in tropical countries, and classically presented with muscle abscesses. Young males between the ages of 10-40 years old are the most susceptible, and often present with a history of blunt trauma. Treatment generally requires a combination of an anti-staphylococcal agent, and an anti-toxic agent blocking bacterial protein-synthesis of PVL. Source control by surgical debridement also plays a major role in the treatment of PVL-infection. Despite agressive treatment, mortality still varies from 0.5% to 2%.

Primary Bacterial Pyomyositis in Children: A Systematic Review.

BACKGROUND: Tropical pyomyositis has had a recent increase in the United States, Europe, and other nontropical areas. The purpose of this study was to provide an accurate description of the demographics, presenting features, sites of involvement, microbiology, imaging modalities, medical and surgical management, complications, and predictors of clinical course. METHODS: We searched PubMed, Cochrane, Web of Science Collection, Scopus, and Embase databases yielding 156 studies. Of these, 23 articles were selected for statistical analysis. RESULTS: The average age at presentation was 8.4±1.9 years with males more commonly affected. Fever, painful limp, and localized pain were the most common presenting symptoms. Pelvis, lower extremity, trunk and spine, in descending order, were the most commonly affected locations. Iliopsoas, obturator musculature, and gluteus musculature were the most commonly affected muscle groups. The mean time to diagnosis was 6.6±3.05 days. Staphylococcus aureus was the most common offending organism. The mean length of hospital stay was 12.0±4.6 days. Medical management alone was successful in 40% of cases (143/361) with an average duration of 9.5±4.0 and 22.7±7.2 days of intravenous and oral antibiotics, respectively. Surgical management consisted of open drainage in 91.3% (199/218) or percutaneous drainage in 8.7% (19/218) of cases. Painful limp, fever, and larger values of white cell count and erythrocyte sedimentation rate were associated with an increased need for surgery. Obturator and calf muscle involvement were strongly associated with multifocal involvement. There were 42 complications in 41 patients (11.3%). Methicillin-resistant S. aureus was associated with an increased risk of complications. The most common complications were osteomyelitis, septicemia, and septic arthritis. CONCLUSIONS: Primary pyomyositis should be considered in cases suggesting pediatric infection. Magnetic resonance imaging is the most commonly used imaging modality; however, ultrasound is useful given its accessibility and low cost. Medical management alone can be successful, but surgical treatment is often needed. The prognosis is favorable. Early diagnosis, appropriate medical management, and potential surgical drainage are required for effective treatment. LEVEL OF EVIDENCE: Level IV-systematic review.

Improving Care and Outcomes for Pediatric Musculoskeletal Infections.

BACKGROUND: Pediatric musculoskeletal infection (MSKI) is a common cause of hospitalization with associated morbidity. To improve the care of pediatric MSKI, our objectives were to achieve 3 specific aims within 24 months of our quality improvement (QI) interventions: (1) 50% reduction in peripherally inserted central catheter (PICC) use, (2) 25% reduction in sedations per patient, and (3) 50% reduction in empirical vancomycin administration. METHODS: We implemented 4 prospective QI interventions at our tertiary children's hospital: (1) provider education, (2) centralization of admission location, (3) coordination of radiology-orthopedic communication, and (4) implementation of an MSKI infection algorithm and order set. We included patients 6 months to 18 years of age with acute osteomyelitis, septic arthritis, or pyomyositis and excluded patients with complex chronic conditions or ICU admission. We used statistical process control charts to analyze outcomes over 2 general periods: baseline (January 2015-October 17, 2016) and implementation (October 18, 2016-April 2019). RESULTS: In total, 224 patients were included. The mean age was 6.1 years, and there were no substantive demographic or clinical differences between baseline and implementation groups. There was an 81% relative reduction in PICC use (centerline shift 54%-11%; 95% confidence interval 70-92) and 33% relative reduction in sedations per patient (centerline shift 1.8-1.2; 95% confidence interval 21-46). Empirical vancomycin use did not change (centerline 20%). CONCLUSIONS: Our multidisciplinary MSKI QI interventions were associated with a significant decrease in the use of PICCs and sedations per patient but not empirical vancomycin administration.

Protrusio acetabulae as a sequel to septic arthritis of the hip with obturator internus pyomyositis.

Pyomyositis is defined as a pyogenic infection of skeletal muscles principally caused by Staphylococcus aureus. It can present either primarily without any associated soft tissue or bone infection or secondary to any surrounding or distant infection focus. Hip pericapsular pyomyositis is one of the most common types of primary pyomyositis. Although many cases are increasingly being described both in tropical and temperate climates, there is no published study regarding the sequelae of untreated pericapsular pyomyositis around the hip joint. The purpose of this study is to describe the sequelae of unaddressed obturator internus abscesses in four adolescent patients and compare their outcome with patients where obturator abscess was also drained using Vanderbilt medial approach. A retrospective study was done with eight patients divided equally into two groups. All the patients were diagnosed as septic arthritis with pyomyositis of obturator internus. Group 1 includes patients treated in between 2012 and 2014 with only hip arthrotomy through anterior approach. Group 2 includes patients treated after 2014 with anterior hip arthrotomy along with drainage of obturator internus abscess. All patients in group 1 had frequent episodes of pain in the first postoperative year with persistent restriction of hip range of motion. Two patients required re-drainage of the hip joint within the first month of indexed surgery. Final follow-up (average 6 years) X-rays revealed grade 2 protrusio acetabuli in three cases and grade 3 in one case as per the Sotelo-Garza and Charnley classification. In contrast to the group 1, group 2 patients had an excellent outcome with an average Iowa Hip Score of 93 at average follow-up of 4.25 years with near normal range of motion, no radiological deterioration and residual pain. The possibility of pericapsular pyomyositis should always be kept in mind, in older children with acute hip pain. A high index of suspicion is required for its early diagnosis. MRI is the gold standard investigation for confirming diagnosis and planning the preferred early surgical treatment. Safe and effective surgical drainage of obturator internus abscess through a minimally invasive Vanderbilt medial approach may prevent long-term sequelae of chronic pain, protrusio acetabuli and secondary osteoarthritis.

Septic emboli from pyomyositis.

Pyomyositis commonly presents with fever, muscle pain and abscess formation involving deep soft-tissue compartments. Staphylococcus aureus is the main causative organism and diagnosis is usually established clinically, supported by imaging, but confirmation may be achieved by histopathological examination. Broad-spectrum antibiotic therapy and surgical debridement are the cornerstone of treatment. Its prognosis is good but, as in all soft-tissue infections, it depends on early intervention, directed antibiotics and, if indicated, prompt surgery. In this paper, we describe a case of pelvic pyomyositis complicated with bacteraemia and bilateral septic pulmonary emboli in a young man in Colombia.

Purulent infectious myositis (formerly tropical pyomyositis).

Purulent infectious myositis (PIM), formerly known as tropical pyomyositis, is a pyogenic infection of skeletal muscles. Staphylococcus aureus, a normal human skin inhabitant, is the main pathogen involved, but multiple other microorganisms have been implicated. Although usually a progressive febrile disease with pain in the affected muscle(s), severe, life-threatening forms have been described, especially in immunosuppressed patients and children. PIM may elude early diagnosis given the lack of overlying skin changes. Hence, high index of suspicion followed by imaging modalities (ultrasonography when superficial and computed tomography or magnetic resonance imaging with contrast when deep) help confirm the diagnosis. Treatment requires combination of percutaneous or open surgical drainage along with antimicrobial therapy guided by culture results. The rising incidence of cases due to methicillin-resistant Staphylococcus aureus (MRSA) strains, makes the inclusion of vancomycin be recommended. This paper reviews PIM highlighting its global distribution, causative agents, predisposing factors, management, and potential complications.

Piriformis Pyomyositis Presenting as Migratory Hip to Knee Pain: A Case Report.

CASE: The authors report a case of piriformis pyomyositis in a teenage female patient with fever and left hip pain. Her pain migrated to the knee with concurrent near resolution of hip pain. Imaging revealed an abscess in the left piriformis with pus tracking along the sciatic nerve sheath. This was complicated by internal iliac vein thrombosis and an embolus to the lung. Open drainage was performed, followed by outpatient intravenous cloxacillin and oral warfarin, with complete resolution of symptoms. CONCLUSION: Piriformis pyomyositis is a rare condition with varying presentations. The threshold for suspicion should be low even in healthy young individuals.

An unusual clinical presentation of tuberculous pyomyositis in a renal allograft recipient.

We present a renal allograft recipient with pulmonary tuberculosis presenting with multiple subcutaneous abscesses involving left forearm, left thigh, suture site and left loin, which on later evaluation revealed to be due to Mycobacterium tuberculosis.

Pyomyositis Diagnosed by Point-of-Care Ultrasound in the Emergency Department.

BACKGROUND: Currently, the role of ultrasound in diagnosing superficial abscesses is well validated, however, its role for deep space infections and intramuscular pathology is limited. Distinguishing between simple cellulitis and abscess is critical for emergency physicians (EP), as the treatment is very different. Management of cellulitis relies on antibiotic therapy, whereas abscess treatment requires incision and drainage. It is important that EPs can accurately distinguish between the two entities. CASE REPORT: We report a case of a 41-year-old man with a history of high blood pressure and poorly controlled diabetes who presented with right lateral thigh redness, warmth, and tenderness. A point-of-care ultrasound (POCUS) of the patient's right lateral thigh with a high-frequency linear (8 MHz) ultrasound probe showed a 2.93 × 3.38 × 6.0-cm complex fluid collection deep to the fascial plane, approximately 3.0 cm from the skin surface, that contained mixed echogenicities with posterior acoustic enhancement consistent with an intramuscular abscess of the vastus lateralis. The patient was diagnosed with pyomyositis of his vastus lateralis. He was started on vancomycin and admitted to the surgical service for antibiotic treatment and surgical drainage. WHY SHOULD EMERGENCY PHYSICIANS BE AWARE OF THIS?: This case demonstrates that the use of POCUS by EPs can facilitate the rapid recognition and treatment of a disease that is challenging to diagnose on physical examination and can be potentially life-threatening if missed. EPs can consider performing a POCUS when evaluating skin infections to ensure rapid diagnosis and appropriate medical care for a potentially severe condition.

Metastatic MSSA infection of the spine and extremities.

Here, we present a rare case of metastatic methicillin sensitive Staphylococcus aureus (MSSA) infection arising from an unknown focus and spreading throughout the lumbar spine with associated pyomyositis of the paraspinal musculature, and septic arthritis of the knee, ankle and sternoclavicular joint. This case highlights the potential for missed aspects and delay in diagnosis in the care of metastatic S. aureus and the need for multispecialty intervention. Treatment of S. aureus infections requires a high index of suspicion and careful examination of multiple organ systems to identify the full extent of the disease. A discussion on metastatic S. aureus infection follows the report.

Septic Arthritis, Osteomyelitis, and Pyomyositis in a Previously Healthy Infant.

Septic arthritis of the shoulder is rare in the pediatric population. In younger children and infants, it can be very difficult to diagnose. Septic arthritis of the shoulder is more commonly associated with concurrent osteomyelitis when compared to septic arthritis of the lower extremity. We describe a case of a 9-month-old patient with septic arthritis, osteomyelitis, and pyomyositis of the shoulder, and a discussion of diagnosis and management of pediatric bone and joint infection in the emergency department setting.

Pelvic pyomyositis in children: changing trends in occurrence and management.

AIMS: We present the largest series of paediatric pelvic pyomyositis from a temperate country, analyse the factors influencing long term prognosis and suggest a diagnostic protocol. MATERIALS AND METHOD: We included 41 patients diagnosed with primary paediatric pelvic pyomyositis between 1998 and 2016, in this study with a mean age of 7.5 years. Demographic, clinical, radiological and follow-up data were reviewed. Statistical analysis was performed to analyse the influence of early diagnosis and treatment on the final outcome. RESULTS: There was an increased occurrence of primary pelvic pyomyositis in the last two years. Of cases identified, 85% fulfilled Kocher's criteria for hip septic arthritis. The mean time to diagnosis was 2.8 ± 0.8 days. The most common muscle affected was obturator internus (65.85%) and multifocal involvement was common (46.34%). Early diagnosis and antibiotic treatment within seven days from the time of onset of symptoms was the only factor that influenced final outcome (p < 0.001). DISCUSSION AND CONCLUSION: Pyomyositis is no longer restricted to tropical countries. The time from onset of symptoms to start of antibiotic treatment influences the final outcome. Clinical examination and inflammatory markers have low specificity in distinguishing between pyomyositis, septic arthritis, osteomyelitis or other infections. MRI is more sensitive and can diagnose pyomyositis in its early stages. Every suspected case of septic arthritis of the hip should undergo an ultrasound. MRI scan may be performed if the ultrasound shows inconclusive evidence of an effusion. Early identification will facilitate early antibiotic treatment which will improve the final outcome. CLINICAL RELEVANCE: There is an increasing occurrence of this tropical disease in temperate countries. Early diagnosis with an MRI scan and early antibiotic use results in good outcomes.