Pyomyositis in the United States 2002-2014

Tropical pyomyositis

Tropical pyomyositis is a serious infectious disease characterised by the formation of abscesses in the skeletal muscles and is primarily caused by Staphylococcus aureus, with an increasing incidence in non-tropical regions. The disease primarily affects men and young adults, often following minor trauma, with an increasing incidence in immunocompromised individuals. Immunocompromised hosts are more likely to be affected by Gram-negative organisms, Mycobacterium tuberculosis, opportunistic infections such as fungal pathogens, non-tuberculous mycobacteria, and Nocardia species. Diagnosis is complicated by non-specific symptoms and the low yield of blood cultures, so imaging studies such as Magnetic Resonance Imaging (MRI) are required for accurate identification. Treatment focuses on controlling the source through drainage, tailored antibiotic therapy, and supportive care, especially in patients with complications such as multi-organ dysfunction. Given the complex clinical manifestations, heightened awareness and a collaborative approach to education and resource provision are critical to improving outcomes in patients with tropical pyomyositis.

Extensive thigh pyomyositis secondary to cystic fistulae due to anaerobic-bacterial infection in a kidney transplant recipient

BACKGROUND

Managing infectious complications after kidney transplantation (KT) remains a major challenge. Infections are the leading non-cardiovascular cause of death among kidney transplant recipients (KTr). The urinary tract is particularly vulnerable to infections in this group, leading to high levels of morbidity and mortality, as well as significant economic costs.

CASE PRESENTATION

This case report presents the first documented instance of extensive thigh pyomyositis resulting from cystic fistulae in an 84-year-old KTr. The patient was referred to our hospital with acute onset fever, pain in the inner thighs and pyuria. A CT scan revealed bilateral pyomyositis of the thighs, characterized by multiple abscesses in the adductor muscles and hydroaerobic levels. Additionally, cystic fistulae complicated by pubic symphysis osteitis were identified.

CONCLUSION

In KTr, lower limb pyomyositis resulting from a urinary tract infection is an extremely rare and significantly worsens the overall prognosis for these patients.

"Iliacus muscle abscess as an unexpected cause of posterior hip pain in a healthy young adult female": a case report

BACKGROUND

Iliacus muscle abscess is an uncommon but potentially life-threatening condition that can present with nonspecific symptoms, posing diagnostic challenges. This case report highlights the importance of considering iliopsoas abscess in patients presenting with fever and hip pain, especially in the absence of obvious risk factors or penetrating trauma. The novelty of this case lies in its atypical presentation mimicking a respiratory viral infection and musculoskeletal injury, impeding accurate diagnosis and appropriate management.

CASE PRESENTATION

A previously healthy 21-year-old female who had a mechanical fall 3 weeks prior presented with fever, right hip pain, and respiratory symptoms, initially suggestive of a respiratory infection and musculoskeletal injury. However, initial investigations revealing a markedly high C-reactive protein (CRP) concentration prompted further computed tomography (CT) imaging of her abdomen and pelvis, which uncovered an iliopsoas abscess presumably stemming from antecedent trauma. Subsequent CT guided aspiration along with culture-sensitive antibiotics led to successful treatment and resolution of her symptoms.

CONCLUSIONS

This case emphasizes the importance of considering iliopsoas abscess as a possible differential, even in young patients without typical risk factors. Markedly elevated inflammatory markers such as CRP concentrations can serve as a vital indicator, directing attention towards the possibility of septicemia or the presence of an occult abscess, facilitating prompt imaging and accurate diagnosis.

Arthritis or an Adjacent Fascial Response? A Case Report of Combined Pyomyositis and Aseptic Arthritis

Pyomyositis, accompanied by aseptic arthritis, has been previously documented in several publications. However, none of the authors in the mentioned case reports offered a pathophysiological explanation for this unusual phenomenon or proposed a treatment protocol. We present a case of a healthy, 70-year-old male who was presented to the emergency department 4 days after tripping over a pile of wooden planks and getting stabbed by a nail to his thigh. The right thigh was swollen. Unproportional pain was produced by a light touch to the thigh. A laboratory test and a CT scan were obtained. The working diagnosis was pyomyositis of the thigh and septic arthritis of the ipsilateral knee. The patient underwent urgent debridement and irrigation of his right thigh. An arthroscopic knee lavage was performed as well. Intraoperative cultures from the thigh revealed the growth of Streptococcus pyogenes and Staphylococcus aureus. Cultures from synovial fluid were sterile; thus, septic arthritis was very unlikely. The source of the knee effusion might have been an aseptic inflammatory response due to the proximity of the thigh infection. Anatomically, the quadriceps muscle inserts on the patella, and its tendon fuses with the knee capsule, creating a direct fascial track from the thigh to the knee. The inflammatory response surrounding the infection may have followed this track, creating a domino effect, affecting adjacent capillaries within the joint capsule, and causing plasma leakage into the synovial space, leading to joint effusion. Our suggested treatment is addressing the primary infection with antibiotics and considering adding anti-inflammatory therapy, given our suspicion that this process has an inflammatory component.

Pectoralis Major Pyomyositis in a Patient With Diabetes: A Case Report and Literature Review

Pyogenic myositis is a bacterial infection of skeletal muscle that is usually caused by Staphylococcus aureus and is common in tropical regions. Recently, this infection has also been reported in immunocompromised patients in temperate regions. The lower extremities and trunk are most affected, while involvement of the chest wall is rare. We report a case of pectoralis major pyomyositis caused by Morganella morganii in an 82-year-old Japanese man with type 2 diabetes mellitus who had undergone stenting for myocardial infarction. Four months prior to visiting our hospital, the patient became aware of pain in the right chest area, which gradually became swollen. One month before the visit, the pain and swelling had become more severe. At the visit, there was swelling in the right anterior thoracic region with a diameter of 10 cm and pain in the same region. On physical examination, his blood pressure was 133/64 mmHg, heart rate was 83 beats/min, and body temperature was 36.9℃. Initially, a sarcoma or other neoplastic lesion was suspected and a needle biopsy was performed. Pus was drained from the puncture site to collect wound culture. Needle biopsy of the lesion did not reveal any fungi or acid-fast bacteria, and a T-SPOT.TB test was negative. Computed tomography and magnetic resonance imaging suggested abscess formation under the pectoralis major muscle. A wound culture test detected Morganella morganii, and pectoralis major pyomyositis was diagnosed. Debridement was performed under general anesthesia. The necrotic pectoralis major muscle was excised, the abscess cavity was opened, and wound irrigation was performed. The postoperative course was good and the patient was discharged on the 16th postoperative day. There has been no recurrence in eight months postoperatively. Pectoralis major pyomyositis may not be relieved by antibiotics alone and may extend to deeper organs to form intrapleural abscesses. Therefore, prompt drainage should be performed to prevent serious complications in a case in which abscess formation is observed.

Wheel of misfortune: A unique case of MRSA pyomyositis of the adductor muscle group from blunt unicycle trauma

In patients with infectious symptoms and severe muscle pain, it is crucial to consider pyomyositis as a significant potential cause. A normal complete blood count should not exclude this possibility early in the course. Early advanced imaging modalities and blood cultures are crucial in narrowing the differential. Methicillin resistant Staphylococcus aureus is increasingly implicated.

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.

Streptococcal pyomyositis in asplenia and underlying connective tissue disease

Pyomyositis is an infection of skeletal muscles, commonly affecting deep longitudinal muscles of the lower extremities. Primary pyomyositis is uncommon in the United States. Staphylococcus aureus is the most common cause of pyomyositis, but Streptococcus pneumoniae is the most common cause of life-threatening bacterial infection in asplenic patients. Most cases of S. pneumoniae pyomyositis occur in immunocompromised patients. We describe a 31-year-old man with S. pneumoniae pyomyositis whose diagnosis and hospital course were complicated by an immunocompromised state from asplenia and an underlying connective tissue disease, Stickler syndrome. Underlying connective tissue diseases such as systemic lupus erythematosus and polymyositis can predispose patients to infection, but susceptibility with Stickler syndrome is less known. While pyomyositis is only seen in up to 0.2% of US hospital admissions, it remains a pertinent differential for patients with asplenia and connective tissue disease.

Primary bacterial intercostal pyomyositis diagnosis: A case report

RATIONALE

Pyomyositis is a microbial infection of the muscles and contributes to local abscess formation. Staphylococcus aureus frequently causes pyomyositis; however, transient bacteremia hinders positive blood cultures and needle aspiration does not yield pus, especially at the early disease stage. Therefore, identifying the pathogen is challenging, even if bacterial pyomyositis is suspected. Herein, we report a case of primary pyomyositis in an immunocompetent individual, with the identification of S aureus by repeated blood cultures.

PATIENT CONCERNS

A 21-year-old healthy man presented with fever and pain from the left chest to the shoulder during motion. Physical examination revealed tenderness in the left chest wall that was focused on the subclavicular area. Ultrasonography showed soft tissue thickening around the intercostal muscles, and magnetic resonance imaging with short-tau inversion recovery showed hyperintensity at the same site. Oral nonsteroidal anti-inflammatory drugs for suspected virus-induced epidemic myalgia did not improve the patient's symptoms. Repeated blood cultures on days 0 and 8 were sterile. In contrast, inflammation of the soft tissue around the intercostal muscle was extended on ultrasonography.

DIAGNOSES

The blood culture on day 15 was positive, revealing methicillin-susceptible S aureus JARB-OU2579 isolates, and the patient was treated with intravenous cefazolin.

INTERVENTIONS

Computed tomography-guided needle aspiration from the soft tissue around the intercostal muscle without abscess formation was performed on day 17, and the culture revealed the same clone of S aureus.

OUTCOMES

The patient was diagnosed with S aureus-induced primary intercostal pyomyositis and was successfully treated with intravenous cefazolin for 2 weeks followed by oral cephalexin for 6 weeks.

LESSONS

The pyomyositis-causing pathogen can be identified by repeated blood cultures even when pyomyositis is non-purulent but suspected based on physical examination, ultrasonography, and magnetic resonance imaging findings.

Rapidly-Progressing Pyomyositis After Chest Contusion in a Patient With Well-Controlled Diabetes Mellitus

Pyomyositis is an uncommon acute bacterial infection of the skeletal muscle. It is sometimes referred to as "tropical pyomyositis" because it has been primarily reported as an endemic disease in tropical regions. In temperate climates, it is mainly diagnosed in immunocompromised persons, such as those with human immunodeficiency virus infection, malignancy, diabetes, and various other medical conditions. Early diagnosis and appropriate antimicrobial therapy for pyomyositis are important, however, it is often missed in its early stage. Herein, we report the case of a patient with obesity and well-controlled diabetes in whom rapid onset pyomyositis developed in only 2 days after chest contusion and induced bacteremia in its early stage. He was successfully treated by antimicrobials without any drainage or surgical intervention. Even in patients with well-controlled diabetes or in healthy persons, pyomyositis should be considered for patients who present with fever and muscle swelling and pain, especially when they have obesity and a history of blunt trauma. It should also be noted that pyomyositis, mimicking muscle contusion or hematoma can appear very early after blunt muscle trauma. Prompt diagnosis and antimicrobial treatment for pyomyositis can lead to a favorable outcome, without surgical drainage.

Gram negative pyomyositis: Two case reports and a review of the literature

Pyomyositis due to Gram negative bacteria is rare. Here we describe two cases in immunocompromised hosts. Both were bacteremic with a Gram-negative bacterium and had impaired immunity related to prolonged and ongoing chemotherapy for hematologic malignancies. Both eventually cleared the infection with a combination of local drainage and systemic antibiotics. This unusual diagnosis should be considered in an immunocompromised patient with muscle pain and fever.

Primary MRSA Myositis Mimicking Septic Arthritis

As the incidence of bacterial myositis and pyomyositis in the United States is rising, we aim to highlight the presentation of bacterial myositis which is known as a great imitator in tropical regions. This is a case report of a 61-year-old female patient with poorly controlled diabetes who presented initially with lateral hip pain and tenderness. This was initially believed to be septic arthritis and warranted arthrocentesis. What makes this case interesting is that what was believed to be a primary community-acquired MRSA myositis, which progressed to a life-threatening septic shock, happened in a nontropical area (Northeastern USA) and in a patient with no underlying recent muscle injury. This case serves to remind clinicians that infectious myositis is gaining more incidence in nontropical regions and can masquerade as septic arthritis, requiring a high index of suspicion. Normal muscle enzymes like CK and aldolase do not rule out myositis.

Disseminated Mycobacterium Avium Complex Myositis in a patient with Graft versus Host disease

Mycobacterium Avium Complex (MAC) is a ubiquitous environmental pathogen that was infrequently reported as a cause of disease prior to the HIV/AIDS epidemic. We present a case of MAC pyomyositis and bacteremia in a 59-year-old man with chronic lymphocytic leukemia in remission after an allogenic stem cell transplant. His post-transplant course was complicated by graft-vs-host disease, requiring treatment with oral steroids and ruxolitinib. In this report we review the literature on disseminated MAC infection in patients living with and without HIV. We also propose a potential mechanism by which this patient may have developed disseminated disease. Disseminated MAC myositis is uncommon in persons living without HIV and requires a high index of suspicion for timely diagnosis.

Neglected tropical rheumatic diseases

The complexities of dealing with rheumatic diseases in tropical countries are diverse and likely due to limited health care infrastructure, lack of diagnostic and therapeutic facilities, impact of dominant prevailing diseases, and the challenges of differentiating from infectious and non-infectious disease mimics. Several tropical diseases present with musculoskeletal and rheumatic manifestations and often pose a diagnostic dilemma to rheumatologists. The diagnosis is often delayed or the disease is misdiagnosed, leading to poor patient outcomes. Endemic tropical diseases like tuberculosis and leprosy have myriad rheumatic presentations and remain important differentials to consider in patients with rheumatic manifestations. Infection with human immunodeficiency virus is a great masquerade and can mimic manifestations of multiple diseases. The role of viral infections in triggering and perpetuating autoimmunity is well known and chikungunya arthritis is a classic example of the same. This review highlights the rheumatic manifestations of tropical diseases and aims to create awareness among the caregivers. Key Points • It is crucial to be aware and identify infectious diseases presenting with rheumatic manifestations in the tropics. • Presentations akin to classic rheumatic syndromes such as rheumatoid arthritis, spondyloarthritis, systemic lupus erythematosus and vasculitis are common.

Readmission after hospitalization with Staphylococcus aureus bacteremia in children

BACKGROUND

Readmission rate is an important quality measure and can inform patient care. However, readmission of S. aureus bacteremia in children requires further research.

METHODS

We performed a population-based longitudinal observational study using the State Inpatient Database from New York, Florida, and Washington, 2009-2015. Children aged 18 years or younger hospitalized with S. aureus bacteremia were included. The outcome of non-elective readmission was assessed by developing Cox proportional hazards regression models.

RESULTS

Of 1240 children with S. aureus bacteremia, 223 (18.0%) and 351 (28.3%) had non-elective readmission within 30 days and 90 days after discharge, respectively. On multivariable analysis, catheter related infection (hazard ratio, HR: 1.79, 95% confidence interval, CI: 1.31-2.45) was associated with 30-day readmission. The median cost of the original hospitalization for S. aureus bacteremia was $29 914 (interquartile range, IQR: $13 276-$71 284), and that of 30 day readmission was $10 956 (IQR: $5765-$24 753).

CONCLUSIONS

S. aureus bacteremia is associated with a high rate of readmission in children, particularly in those with catheter related infection. Hospitalization with S. aureus bacteremia and readmission are costly. Future research should seek interventions to improve outcomes of S. aureus bacteremia in children, and the results of this study can serve as a benchmark.

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

OBJECTIVES

Pyomyositis, an acute bacterial infection of skeletal muscle usually resulting in abscess formation, is well recognised in tropical regions where it can account for up to 4% of adult surgical admissions. It is increasingly being reported from high-income temperate countries. Pyomyositis occurs across all ages and in both sexes. Mortality ranges from 1% to 23%. Many risk factors have been suggested. We aimed to identify factors associated with pyomyositis.

METHODS

We undertook a systematic review and meta-analysis, using PubMed, EMBASE, Scopus and the Cochran Library and hand-searching published papers. The random-effects model meta-analysis was used to calculate pooled estimated odd ratios with the corresponding 95% confidence interval.

RESULTS

All studies in the systematic review (n = 25) and the meta-analysis (n = 12) were hospital-based. Seven only included children. Relatively few studies have been published in the last decade, the majority of which are from high-income temperate settings. Staphylococcus aureus was the main organism isolated. Males under the age of 20 predominated, and mortality of up to 20% was reported. Factors associated with pyomyositis were HIV infection (OR = 4.82; 95% CI: 1.67-13.92) and fulfilling an AIDS surveillance definition (OR = 6.08; 95% CI: 2.79-13.23).

CONCLUSIONS

Our meta-analysis indicated significant associations between pyomyositis infection and HIV/AIDS. Major gaps in our understanding of the epidemiology, pathogenesis, clinical presentation, and outcome remain, highlighting the need for further research and more systematic studies. Pyomyositis merits consideration as a neglected tropical disease.

Infections of the Peripheral Nervous System

PURPOSE OF REVIEW

This article describes infections that affect the peripheral nervous system, including their clinical features, differential diagnoses, and treatments.

RECENT FINDINGS

Rates of pyomyositis have increased recently in the United States, possibly because of an increase in risk factors such as IV drug use, obesity, and diabetes. Other peripheral nervous system infections, such as diphtheria, have become more common in older patients secondary to a lack of revaccination or waning immunity. Although recommended treatment regimens for most infections remain unchanged over recent years, debate over the ideal dosing and route of administration continues for some infections such as tetanus and leprosy (Hansen disease).

SUMMARY

Infections of the peripheral nervous system are varied in terms of the type of infection, localization, and potential treatment. Nerve conduction studies and EMG can help determine localization, which is key to determining an initial differential diagnosis. It is important to recognize infections quickly to minimize diagnostic delays that could lead to patient morbidity and mortality.

Emergency physician-performed bedside ultrasound of pyomyositis

Point-of-care ultrasound (POCUS) is an indispensable tool for emergency physicians in the rapid bedside diagnosis of skin and soft tissue infections. The utility of POCUS for the differentiation of cellulitis and subcutaneous abscess is well established; however, there is a paucity of studies highlighting POCUS as a first-line imaging approach for pyomyositis, an uncommon skeletal muscle infection and/or intramuscular abscess formation requiring emergent diagnosis. This report describes a case in which emergency physician-performed POCUS led to the early detection and timely management of pyomyositis in the emergency department.

Pyomyositis and Infectious Myositis: A Comprehensive, Single-Center Retrospective Study

Background

Pyomyositis is a bacterial infection of skeletal muscle that classically leads to abscess formation. A related, but distinct, entity is infectious myositis. The epidemiology of these infections has changed in recent years.

Methods

To better characterize both pyomyositis and infectious myositis, we conducted a retrospective study at our tertiary care institution. We identified 43 cases of pyomyositis and 18 cases of infectious myositis treated between January 2012 and May 2020.

Results

The mean age of patients was 48 years, and 66% were male. Diabetes mellitus affected one third of patients, and 16% had other immunocompromising comorbidities. Staphylococcal species accounted for 46% of all infections, and common symptoms included muscle pain (95%) and subjective fever (49%). Altered mental status was a presenting symptom in 16% of cases. Approximately half of all patients received >1 class of antibiotic, and the median length of antimicrobial therapy was 18 days. Open and percutaneous drainage procedures figured prominently in the management of these infections, with 28% of patients requiring multiple procedures. Pathology specimens were available for 12 of 61 cases. Overall, the treatment success rate was 84%.

Conclusions

Gram-positive bacteria accounted for most infections at our institution, and management commonly involved open or percutaneous drainage procedures. Future studies that prospectively evaluate treatment strategies for pyomyositis and infectious myositis are warranted.

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.