“Tropical” pyomyositis. An unusual infection due to staphylococcus aureus

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.

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.

Focal pyomyositis caused by Enterobacter in an immunocompetent patient: A case report

Pyomyositis is a pyogenic infection of skeletal striated muscle, usually found in tropical areas, often in immunocompromised patients. We report a new observation of a nontropical Enterobacter pyomyositis occurring in an immunocompetent female in Tunisia. A 53-year-old patient presented with acute fever and intense myalgia in the right thigh. On clinical examination she had an altered general condition, a fever at 40°C and an important swelling of the lateral side of the right thigh. In biology, she had an inflammatory syndrome. Blood culture had identified Enterobacter. Muscle magnetic resonance imaging showed diffuse inflammatory involvement of the vastus lateralis muscle of the right quadriceps associated with edematous infiltration of subcutaneous fatty tissues. Diagnosis of pyomyositis was retained. Antibiotic therapy initially probabilistic and then adapted to the antibiogram was initiated with a favorable outcome. Although rare outside the tropics, the potential severity of pyomyositis encourages its better knowledge.

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.

Tuberculous pyomyositis presenting as septic arthritis and multiple site pyomyositis

Primary tropical pyomyositis, commonly caused by Staphylococcus aureus, is characterised by suppuration in skeletal muscles, which manifests as single or multiple abscesses. Another rare causative organism is Mycobacterium tuberculosis in endemic areas. Here, we report a case of primary tuberculous pyomyositis presenting as septic arthritis of the right knee and multiple site pyomyositis of the right thigh and chest wall. A tuberculous aetiology was overlooked at first, which resulted in a diagnostic delay. The patient was initially diagnosed, using ultrasonography, MRI and an absence of systemic symptoms of tuberculosis, with bacterial pyomyositis and treated with broad-spectrum antibiotics. However, further investigations performed on knee joint aspirate yielded negative cultures and a positive cartridge-based nucleic acid amplification test, which, along with a non-resolution of his symptoms, suggested a primary tuberculous pyomyositis. He was successfully managed with incision and drainage of the lesions and completion of anti-tubercular therapy.

Pelvic Pyomyositis in Childhood: Clinical and Radiological Findings in a Tertiary Pediatric Center

Pyomyositis (PM) is an infrequent but increasing bacterial infection of the skeletal muscle, with muscles of the pelvis and thigh frequently involved. The diagnosis is often challenging, especially when a deep muscle is affected. We present a single-center pediatric cohort affected by pelvic PM. A retrospective analysis was performed, including children admitted to Meyer Children’s Hospital between 2010 and 2020. Demographic, anamnestic, clinical, laboratory, radiological and management data were collected. Forty-seven patients (range 8 days–16.5 years, 66% males) were selected. Pain (64%), functional limitations (40%) and fever (38%) were the most common presenting symptoms; 11% developed sepsis. The median time to reach the diagnosis was 5 days (IQR 3–9). Staphylococcus aureus was the most common organism (30%), Methicillin-Resistant S aureus (MRSA) in 14%. PM was associated with osteomyelitis (17%), arthritis (19%) or both (45%). The infection was multifocal in 87% of children and determined abscesses in 44% (40% multiple). Pelvic MRI scan, including diffusion-weighted imaging (DWI), always showed abnormalities when performed. Clinical and laboratory findings in pelvic PM are unspecific, especially in infancy. Nevertheless, the infection may be severe, and the suspicion should be higher. MRI is the most useful radiological technique, and DWI sequence could reveal insidious infections.

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.

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.

Acute Proximal Myopathy in a Young Male—A Case of Infectious Myositis

Background and objectives: Acute proximal muscle weakness has a broad differential. Infectious myositis is difficult to differentiate clinically from inflammatory myopathy, often causing a delayed diagnosis. Infectious myositis should be thought of as a differential for proximal muscle pain and weakness in the right context. Case Presentation: A 40-year-old male with diabetes presented with exquisite pain and weakness of proximal extremities. He denied trauma, recent travel, new medications, or substance use. He denied prior rheumatologic, thyroid, or musculoskeletal disorders. The urine culture revealed staphylococcal infection with negative blood cultures. Rheumatologic and endocrine workups were negative. Random muscle biopsy was negative for inflammatory infiltrate. MRI of thighs and arms showed innumerable foci of nodular and ring enhancement in the proximal muscle groups. The patient noted improvement after about 10 days of antibiotics with complete resolution at 2 months. Discussion and Conclusion: Bacterial myositis is most often due to Staphylococcus aureus (70%) and affects a single muscle. Multifocal abscesses are rare and strongly suggest transient bacteremia. Our patient most likely had transient initiating staphylococcal bacteremia leading to diffuse myositis and hematogenous urinary tract infection (UTI). A delay in treatment can be life-threatening.

Pyomyositis in the setting of complicated diverticulitis: case report

Pyomyositis is typically thought of as a disease of the tropics. However, it is becoming more prevalent in temperate regions, and may be underdiagnosed. Here, pyomyositis is encountered as a complication of perforated diverticulitis, which has not been previously reported. A 61-year-old Caucasian man initially presented in respiratory distress and was diagnosed with respiratory failure due to COPD exacerbation. The patient was taking high-dose prednisone, 60 mg daily for the past 2 years. Initially, he was afebrile, normotensive, tachycardic to 178 beats/minute and tachypneic to 28 breaths/minute, requiring noninvasive ventilation to maintain oxygenation. Blood tests revealed leukocytosis of 16.7×10³/μL, and blood cultures grew Escherichia coli. Broad-spectrum antibiotics were started but leukocytosis and bacteremia persisted on repeated tests. On the seventh hospital day, a CT scan of the abdomen was performed for complaints of abdominal pain, and the patient was diagnosed with Hinchey stage 3 diverticulitis. A Hartmann’s procedure was performed with intraoperative findings of purulent peritonitis. Intraoperative cultures grew E. coli and vancomycin-resistant Enterococcus faecium. The patient continued to have leukocytosis of 15.1×10³/μL despite surgical therapy. He began to complain of left lower extremity pain, and a CT scan on hospital day 24 revealed gluteal intramuscular abscesses, which were percutaneously drained. Persistent symptoms prompted another CT scan on hospital day 28, which revealed additional intramuscular abscesses in the vastus lateralis muscle, which was also drained, with subsequent resolution of pain and normalization of inflammatory markers. This is the first case demonstrating pyomyositis as a complication of diverticulitis. While the mechanism of pyomyositis may not be unique, it is important to recognize the potential complications of frequently encountered diseases. In this critically ill and immunosuppressed patient, there was delayed diagnosis of both diverticulitis and pyomyositis, but the patient quickly improved once the diseases were recognized and treated.

Obturator externus abscess in a 9-year-old child: A case report and literature review

RATIONALE

Obturator pyomyositis is a rare condition in children. Diagnosis is often delayed because of its rarity, and the vagaries of its presentation cause it to be easily be missed. Physicians should therefore familiarize themselves with this condition and consider it as a possible differential diagnosis in patients presenting with an acutely painful hip. Inflammatory syndrome is also frequent among sufferers and the MRI is a very sensitive diagnostic tool for obturator pyomyositis. Additionally, joint fluid aspirations and blood cultures are also useful in identifying the pathogen. The appropriate antibiotic therapy provides a rapid regression of symptoms during the early stage of pyomyositis. In cases of MRI-confirmed abscess, surgical treatment is indicated.

PATIENT CONCERNS

Our report focuses on a case of obturator pyomyositis in a 9-year-old boy. The child was febrile for 5 days and could only manage to walk a few steps. His hip range of motion was restricted in all directions. In addition, the patient had presented pain and swelling of his right elbow for a day, with a restriction of motion in the joint. There was a clear inflammatory syndrome. A diagnosis of hip and elbow septic arthritis was suspected, and the child underwent joint aspiration of the both cited joints. The aspiration of the elbow returned pus. Conversely, no effusion was found in the hip aspiration. The administration of empiric intravenous antibiotherapy was started.

DIAGNOSES

An MRI revealed an osteomyelitis of the ischio-pubic area associated with a subperiosteal abscess.

INTERVENTIONS

Subsequently, 3 days after elbow arthrotomy, a surgical treatment was performed on the patient's right hip in order to evacuate the subperiosteal abscess and muscular collection because of the persistence of the patient's symptoms and inflammatory syndrome despite susceptible intravenous antibiotics. Postsurgery the patient showed steady improvement.

LESSONS

Such cases demonstrate how diagnosis can be difficult because pelvic pyomyositis is often mistaken for more common pathologies such as septic arthritis, osteomyelitis, or appendicitis. This may delay the diagnosis or refer misdiagnosis. We discuss this rare infection in light of the literature with particular reference to its incidence, clinical features, bacteriological etiology, biological, and radiological presentation, and above all, its treatment.

Pyomyositis is not only a tropical pathology: a case series

Background

Pyomyositis is an acute bacterial infection of skeletal muscle that results in localized abscess formation. This infection was thought to be endemic to tropical countries, and is also known as “tropical pyomyositis”. However, pyomyositis is increasingly recognized in temperate climates and is frequently associated with an immunosuppressive condition, such as human immunodeficiency virus, malignancy, and diabetes mellitus. It is also found in healthy and athletic people after strenuous or vigorous exercise or following localized and possibly unnoticed trauma. It can be primary or secondary to neighboring or remote infection. Primary pyomyositis is a rare condition that can affect children and adolescents. Diagnosis can be delayed because the affected muscle is deeply situated and local signs are not apparent. This delay in diagnosis can result in increased morbidity and a significant mortality rate. The pediatric population, which comprises 35% of the reported pyomyositis cases, is an especially difficult subset of patients to diagnose.

Case presentation

In our series, we describe the cases of four previously healthy Caucasian children who were admitted to our Pediatric Department with different clinical presentations. Pyomyositis in our patients was related to factors affecting the muscle itself, including strenuous exercise and direct muscle trauma. Therapy was started with a cephalosporin antibiotic and teicoplanin was subsequently added. The minimum length of therapy was 3 weeks.

Conclusions

The diagnosis of pyomyositis in our patients, none of whom were immune-compromised, is confirmation that this disease is not an exclusive pathology of tropical countries and demonstrates that there is an increasing prevalence of pyomyositis in temperate climates.

Primary psoas abscess caused by group A streptococcus in a child: Case report with microbiologic findings

Primary abscess of the iliopsoas muscle in children is uncommon, especially due to Streptococcus pyogenes (group A streptococcus: GAS), which causes a variety of diseases ranging from pharyngitis to invasive life-threatening infection. We present primary iliopsoas abscess in a nine-year-old boy presenting with fever, mild disturbance of consciousness, limp, and pain in the right loin. Magnetic resonance imaging and isolation of GAS from both blood and abscess samples led us to the confirmative diagnosis. The patient recovered after treatment comprising drainage and intravenous antibiotics. The CovRS system is one of the best-characterized systems with two-component signal transduction in the GAS, and mutations in covRS induce overproduction of various virulence factors that play a crucial role in invasive GAS infection. RopB, also known as a GAS regulator, influences the expression of multiple regulatory networks to coregulate virulence factor expression in GAS. In the present case, sequence analysis revealed the isolated GAS as emm type 6 with alterations in covS, whereas the covR and ropB genes were intact. The covS alterations might have influenced the virulence of the strain causing this severe GAS infection.

Streptococcus agalactiae pyomyositis in diabetes mellitus

Pyomyositis is an acute infectious disorder affecting the skeletal muscle. Although seen more commonly in the tropics, cases are being reported in temperate countries, including the United States. We report a case of nontropical pyomyositis in a 58-year-old diabetic man who presented with a vague chest wall swelling. His initial clinical presentation and imaging findings suggested an intramuscular hematoma. He later developed fever with increased swelling, and pyomyositis was diagnosed after an aspiration of the swelling yielded Streptococcus agalactiae. Aspiration of the abscess and the use of appropriate antibiotics led to complete resolution of the disease. We discuss possible factors in diabetics that might predispose them to pyomyositis.

Case of disseminated pyomyositis in poorly controlled type 2 diabetes mellitus with diabetic ketoacidosis

Primary pyomyositis is a pyogenic and uncommon infection of skeletal muscle, which is mainly observed in tropical areas and/or human immunodeficiency virus patients. In non‐human immunodeficiency virus infected patients, the most common cause is diabetes mellitus. Because of its rarity, the accurate diagnosis is often challenging. Staphylococcus aureus is the most common causative bacteria. According to the severity, pyomyositis is divided into three stages, and the late stage is occasionally lethal. The present case was compatible with the most advanced stage. Therefore, it was very difficult to save her life without precise and timely diagnosis. Furthermore, in the invasive stage, surgical drainage and broad‐spectrum antibiotics should be given for a long enough period. Here, we report a case of a Japanese woman who developed disseminated abscesses under poorly controlled diabetic conditions accompanied by ketoacidosis, but was successfully treated without any sequelae.

Staphylococcus aureus-Associated Musculoskeletal Infections

Musculoskeletal infections caused by Staphylococcus aureus are among the most difficult-to-treat infections. S. aureus osteomyelitis is associated with a tremendous disease burden through potential for long-term relapses and functional deficits. Although considerable advances have been achieved in diagnosis and treatment of osteomyelitis, the management remains challenging and impact on quality of life is still enormous. S. aureus acute arthritis is relatively seldom in general population, but the incidence is considerably higher in patients with predisposing conditions, particularly those with rheumatoid arthritis. Rapidly destructive course with high mortality and disability rates makes urgent diagnosis and treatment of acute arthritis essential. S. aureus pyomyositis is a common disease in tropical countries, but it is very seldom in temperate regions. Nevertheless, the cases have been increasingly reported also in non-tropical countries, and the physicians should be able to timely recognize this uncommon condition and initiate appropriate treatment. The optimal management of S. aureus-associated musculoskeletal infections requires a strong interdisciplinary collaboration between all involved specialists.

Neurologic infections in diabetes mellitus

Even at a time when HIV/AIDS and immunosuppressive therapy have increased the number of individuals living with significant immunocompromise, diabetes mellitus (DM) remains a major comorbid disorder for several rare but potentially lethal infections, including rhino-orbital-cerebral mucormycosis and malignant external otitis. DM is also a commonly associated condition in patients with nontropical pyomyositis, pyogenic spinal infections, Listeria meningitis, and blastomycosis. As West Nile virus spread to and across North America over a decade ago, DM appeared in many series as a risk factor for death or neuroinvasive disease. More recently, in several large international population-based studies, DM was identified as a risk factor for herpes zoster. The relationships among infection, DM, and the nervous system are multidirectional. Viral infections have been implicated in the pathogenesis of type 1 and type 2 DM, while parasitic infections have been hypothesized to protect against autoimmune disorders, including type 1 DM. DM-related neurologic disease can predispose to systemic infection - polyneuropathy is the predominant risk factor for diabetic foot infection. Because prognosis for many neurologic infections depends on timely institution of antimicrobial and sometimes surgical therapy, neurologists caring for diabetic patients should be familiar with the clinical features of the neuroinfectious syndromes associated with DM.

Tropical pyomyositis

Background:

Tropical pyomyositis is characterized by suppuration within skeletal muscles, manifesting as single or multiple abscesses. Though primarily a disease of tropics, it is increasingly being reported from temperate regions in immunosuppressed patients. However, India has only few sporadic case reports.

Aims:

The aim of this study is to evaluate the causative organisms, clinical presentations, diagnostic modalities, treatment protocols and outcome data in tropical pyomyositis patients.

Subjects and Methods:

The study was carried out in Nilratan Sircar Medical College and Hospital, Kolkata over 3 years (July 2010 to June 2013). A total of 12 patients were diagnosed with tropical pyomyositis (confirmed with aspiration and culture of pus from muscle). All the investigation and treatment data were recorded systematically.

Results:

The presenting feature was high fever and myalgia in all 12 patients. Quadriceps femoris was the most commonly involved muscle (50%); followed by iliopsoas (25%). Culture of the aspirate showed Staphylococcus aureus in nine patients (75%), Klebsiella pneumonia in one patient (8.33%) and no growth in two patients (16.67%) even after tubercular and fungal culture.

Conclusions:

Tropical pyomyositis can affect immune-competent individuals. S. aureus is the most commonly cultured organism. Immediate initiation of appropriate antibiotics and surgical debridement are required to avoid complications. The prognosis remains excellent if promptly treated.

Primary obturator internus and obturator externus pyomyositis

Background

Pyomyositis is a rare condition in immune competent patients and is usually seen in tropical countries. Pyomyositis of obturator muscles in particular is an extremely rare condition, which causes hip pain and mimics septic arthritis.

Case Report:

This is a case report of a 9-year-old boy without an underlying disease or a compromised immune system, who presented with knee pain that progressed to hip pain and inability to bear weight. He was diagnosed initially with septic arthritis of the hip and underwent unnecessary hip exploration surgery. Magnetic resonance imaging scan was performed postoperatively and showed pyomyositis of obturator internus and obturator externus muscles. He was managed medically and had a good outcome.

Conclusions:

A greater awareness of this emergency condition is necessary to prevent misdiagnosis, unnecessary surgical intervention, and to avoid the devastating possible complications of delayed diagnosis.

Emergency department diagnosis of a quadriceps intramuscular loculated abscess/pyomyositis using dynamic compression bedside ultrasonography

Introduction

A 73-year-old man with a past medical history of myelodysplastic syndrome and recent chemotherapy presented to the emergency department with a 1-week history of progressively increasing left thigh pain and swelling. His physical examination revealed left anterolateral diffuse thigh swelling with no erythema or warmth to palpation. The anterolateral quadriceps was markedly tender to palpation. Emergency department bedside dynamic compression ultrasonography that was performed on the left anterolateral thigh revealed a quadriceps intramuscular abscess with loculated yet movable pus.

Conclusion

Bedside dynamic compression ultrasonography can assist the emergency or critical care physician in the diagnosis of quadriceps intramuscular abscess or pyomyositis.

Iliopsoas abscess--a review and update on the literature

Iliopsoas abscess is a rare condition with a varied symptomology and aetiology. Patients with this condition often present in different ways to different specialities leading to delays in diagnosis and management. Recent advances in the radiological diagnosis of this traditionally rare abscess have highlighted that there is a lack of evidence relating to its aetiology, symptomology, investigation and management. This article reviews the currently available literature to present a concise and systematic review of iliopsoas abscess.

Abscesso epidural em paciente portador de piomiosite tropical: relato de caso e revisão da literatura

A piomiosite é uma infecção muscular profunda subaguda que pode originar abscessos intramusculares únicos ou múltiplos. Está associada a infecções sistêmicas, diabetes mellitus, terapia imunossupressora, AIDS e mieloma múltiplo. Descrevemos um caso de piomiosite tropical com acometimento da coluna vertebral que evoluiu para abscesso epidural, em paciente com história pregressa de espondilite anquilosante em tratamento com medicações imunossupressoras e apresentou trauma direto na coxa direita previamente ao início dos sintomas. O objetivo deste trabalho é descrever o acometimento raro da coluna vertebral em pacientes com piomiosite tropical, com apenas um caso descrito na literatura mundial, destacando a necessidade dos métodos complementares na investigação diagnóstica para o adequado tratamento e as possíveis complicações dessa doença. Os pacientes imunossuprimidos com dores musculares subagudas devem ser investigados quanto à piomiosite tropical e o diagnóstico precoce é fundamental para o sucesso do tratamento.

Primary obturator-muscle pyomyositis in immunocompetent children

PURPOSE

Primary pyomyositis in immunocompetent children in non-tropical regions (countries with temperate climates) is very uncommon. It is rarely found in the intrapelvic muscles, and even more rarely in the obturator muscles. We try to draw attention to the potential occurrence in these conditions.

METHODS

Five new cases of primary obturator-muscle pyomyositis in immunocompetent children aged between 6 and 11 years in a temperate climate are presented. They present with symptoms as follows: fever, pain (thigh, abdominal, inguinal, and/or hip pain), and limp. Three of them had no hip movement limitation. All of them had tenderness in the perineum zone.

RESULTS

Laboratory tests may reveal high erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) counts, but depend on the length of diagnostic delay. The evolution time oscillated from 1 to 5 days. Fever and limp disappearance depends on the evolution time previous to the onset of the antibiotics administration. In 4 out of 5 patients, Staphylococcus aureus was present in the blood cultures. In all cases of obturator-muscle pyomyositis, diagnosis was confirmed using computed tomography (CT) scan (one) and/or magnetic resonance imaging (MRI) (four).

CONCLUSIONS

Obturator-muscle pyomyositis is aimed at emphasizing the diagnostic difficulties associated with the condition, due to its deep location and to the fact that the disease presents with multiple manifestations that may initially cause confusion, since they mimic other conditions occurring in the abdomen, hip (septic arthritis, osteomyelitis), spine, etc. The diagnosis is only confirmed using CT scan and/or MRI. In the five patients with antibiotics treatment, the condition resolves without sequelae, even at long-term follow-up.

Pneumococcal pyomyositis: report of 2 cases and review of the literature

Streptococcus pneumoniae is an uncommon cause of pyomyositis. It is unclear whether the clinical presentation and outcome of pneumococcal pyomyositis differ depending on the host's underlying immune status. We describe 2 patients with pneumococcal pyomyositis, review all published cases, and compare characteristics between apparently healthy hosts and at-risk hosts. A total of 35 cases of pneumococcal pyomyositis were identified, 11 in apparently healthy hosts and 24 in at-risk hosts. Two-thirds of the patients had an antecedent respiratory illness or meningitis. At-risk hosts tended to have a longer interval between the development of symptomatic muscle infection and the diagnosis of pyomyositis and a significantly higher risk of disseminated disease at presentation, as manifested by involvement of multiple noncontiguous muscles or presence of meningitis. Overall, other than 1 death, all patients recovered with antibiotics and surgical drainage, but as might be expected there was a significantly higher rate of complications among at-risk hosts.

Primary pyomyositis of the pelvis in children: a retrospective review of 8 cases

Primary pyomyositis of the pelvic musculature is a condition rarely seen in temperate climates, although its frequency has been increasing in the United States. The condition should be considered in the initial differential diagnosis of an adolescent presenting with fever, difficulty ambulating, and hip pain. This is a retrospective review of 8 cases of primary pelvic pyomyositis in patients aged 18 years or younger who were treated at the Children's Medical Center in Augusta, Georgia. The site of infection was the obturator internus in the majority of the cases (5). The site was the gluteus, iliopsoas, and iliacus in 1 case each. Four patients who were diagnosed early responded to intravenous antibiotics with no need for further intervention. Two patients required incision and drainage of an abscess combined with antibiotics. Two patients had prolonged hospital courses requiring intensive unit care and mechanical ventilation. Blood cultures were positive in 87.5% of patients, and all patients presented with elevated acute phase reactants. One of the most difficult diagnostic aspects of presentation is an inconclusive symptom profile. It is noteworthy that patients with pelvic pyomyositis may present with limited range of motion in a specific plane (the motion placing the infected muscle on stretch) vs global limited range of motion of the joint as is commonly seen in septic arthritis. Early diagnosis is essential to prevent systemic illness and complications associated with this condition. Magnetic resonance imaging with gadolinium is helpful to diagnose and guide treatment.

Pyomyositis

Pyomyositis is the primary infection of the skeletal muscle. It is common in the tropics, but is increasingly being reported worldwide. It can affect immunocompromised and immunocompetent individuals. Staphylococcus aureus is the most common causative organism. Muscle histology and its culture remain the gold standard for diagnosis. However, among noninvasive methods, MR imaging is highly sensitive and can image large areas of the body and detect subclinical involvement. Early diagnosis, institution of appropriate antibiotic therapy, and drainage of pus lead to favorable outcome.

Pyomyositis

Poorly controlled diabetes is associated with an increased risk of infectious complications. With the increasing prevalence of diabetes, many more people are being looked after in primary care. We describe a case of pyomyositis, a potentially severe but uncommon complication of poorly controlled diabetes that was not recognised in the community. Clinicians looking after people with diabetes need to be aware that prolonged, unexplained symptoms need specialist assessment.

A 31-year-old female with fever and back pain

Primary pyomyositis is a suppurative infection of striated muscle, the diagnosis of which is overlooked or delayed due to its rarity and vague clinical presentation. Though rare in the United States and temperate zones, pyomyositis is more frequently reported from tropical countries. The exact pathogenesis of pyomyositis is uncertain in most cases. The disease progresses through three stages with characteristic features and require a high index of suspicion to institute stage-wise treatment. Newer imaging methods, particularly magnetic resonance imaging, have facilitated the accurate diagnosis of the infection and of the extent of involvement. Early recognition with appropriate antibiotics in the pre-suppurative stage and prompt surgical intervention in the late stages form the corner stone of treatment. Delay in diagnosis can result in increased morbidity and mortality, especially in diabetics and immunocompromised state. Here, we report a case of primary paraspinal pyomyositis in a middle-aged female and emphasize the importance of early diagnosis and treatment.

Clinical characteristics and predictors of mortality in 67 patients with primary pyomyositis: a study from North India

Primary pyomyositis is infection of the skeletal muscles in the absence of adjacent skin, soft tissue, and bone infection. This study was undertaken to look at the spectrum of clinical presentations, therapeutic interventions, and their outcomes and also to evaluate the association of various risk factors with mortality. This was a retrospective study in which the patients admitted with the diagnosis of primary pyomyositis from January 2000 to June 2007 were included. Their demographic details, clinical and laboratory data, Sequential Organ Failure Assessment (SOFA) score at presentation, treatment instituted, complications encountered, and hospital outcome were recorded. Sixty-seven patients (42 males and 25 females) with a diagnosis of primary pyomyositis were included. Median age at the time of presentation was 37 years (interquartile range = 25-50 years). Common presenting symptoms were myalgias [50 (74.62%)] and fever [49 (73.13%)]. Twenty-six patients had underlying predisposing medical conditions. The commonest muscle group involved was iliopsoas muscles in 31 (46.26%) patients. Methicillin-sensitive Staphylococcus aureus was the commonest organism isolated from the pus. Twenty-eight patients developed sepsis and seven died. On univariate analysis, there was a statistically significant association between higher SOFA score, lower Glasgow coma scale, higher pulse rate, lower blood pressure, raised blood urea, raised serum creatinine, higher serum glutamic pyruvate transaminase, raised total bilirubin at presentation, and development of sepsis during hospital stay with mortality. In our study, the patients were seen almost a decade later than those seen in other studies from the region. Evidence of organ dysfunction at presentation and sepsis was associated with increased mortality.

Pyomyositis in children: early diagnosis and treatment

PURPOSE

This study was conducted to evaluate early diagnosis, clinical course, and treatment outcome in children with pyomyositis.

METHODS

Between 2001 and 2006, 6 children with a mean age of 7.2 years were diagnosed and treated for pyomyositis in our clinic. The most common site of involvement was the hip and thigh region. All patients underwent early magnetic resonance imaging (MRI) examination that played a significant role in the early diagnosis and management of the disease.

RESULTS

Staphylococcus aureus was the most common pathogen and was identified in 3 cases. Intravenous antibiotics were administered and were followed by oral agents for an additional period. The duration of therapy ranged from 3 to 6 weeks. No surgical intervention was needed. Magnetic resonance imaging was used to evaluate response to the therapy.

CONCLUSIONS

Although pyomyositis is a rare disease, it should be considered in the differential diagnosis of immediate onset of musculoskeletal pain in children. Early diagnosis and antibiotic treatment are important as major complications such as abscess formation and sepsis can be avoided. Having a high sensitivity to reactive inflammatory changes, MRI is a valuable tool in the armamentarium of the clinician in early diagnosis of pyomyositis.

Pyomyositis due to Streptococcus pneumoniae

Pyomyositis is an unusual but potentially serious disease in children. Staphylococcus aureus is the most commonly implicated pathogen, but pneumococcal pyomyositis is very rare. Clinical diagnosis of pyomyositis can be difficult often mimicking septic arthritis of the hip or appendicitis. We report a 12-year-old male with pyomyositis caused by Streptococcus pneumoniae who presented with fever and severe right hip and abdominal pain. Magnetic resonance imaging of the right hip revealed the diagnosis of pyomyositis. Blood cultures grew Streptococcus pneumoniae, sensitive to penicillin, ceftriaxone, and clindamycin. He was successfully treated with a 3-week course of clindamycin. Early recognition, appropriate antibiotic therapy, and if indicated, drainage of the muscle abscess is critical to reduce morbidity and mortality.

Tropical primary pyomyositis in children of the UK: an emerging medical challenge

Pyomyositis is a commonly encountered condition in the tropics. It was not described in the UK until 1998. The reason for the increasing incidence is not understood. We sought to identify the experience gained of this condition within a UK paediatric tertiary referral unit. Retrospective review of cases of pyomyositis from our institution since 1998 was undertaken to identify demographics, presentation, diagnosis and management. Thirteen cases were identified. The obturator internus was most commonly affected (62%). Staphylococcus aureus was cultured in nine cases (69%). One diagnostic retroperitoneal exploration was performed and all cases were identified by computed tomography or magnetic resonance imaging. To our knowledge, this is the first UK series of pyomyositis, reflecting its increasing Western incidence. Early diagnosis and treatment with antibiotics is all that is needed in the majority of cases. A greater awareness of this emerging condition is necessary to prevent misdiagnosis and unnecessary surgical intervention by all surgeons.

Pyomyositis mimicking leptospirosis: two cases in a Brazilian tertiary care hospital in a non-tropical area

Pyomyositis is a subacute, deep suppurative bacterial infection of skeletal muscle not arising from contiguous infection. It is presumably haematogenous in origin, and characterized by muscle pain and swelling. We report on two patients who presented with pyomyositis in a tertiary care hospital in temperate region located in southern Brazil with a clinical presentation, which was initially suggestive of leptospirosis. This report discusses the pathogenesis, clinical presentation, diagnosis and management of pyomyositis. Physicians living in non-tropical areas should note that pyomyositis might occur in those areas, and its initial clinical presentation may be similar to leptospirosis.

Community-associated methicillin-resistant Staphylococcus aureus

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has emerged over the last decade across the United States and the world, becoming a major pathogen in many types of community-acquired infections. Although most commonly associated with minor skin and soft tissue infections, such as furuncles, CA-MRSA also can cause necrotizing fasciitis, pyomyositis, osteoarticular infections, and community-acquired pneumonia. This article discusses the epidemiology, diagnosis, and management of these infections from the perspective of the emergency physician.

Bacterial, fungal, parasitic, and viral myositis

Infectious myositis may be caused by a broad range of bacterial, fungal, parasitic, and viral agents. Infectious myositis is overall uncommon given the relative resistance of the musculature to infection. For example, inciting events, including trauma, surgery, or the presence of foreign bodies or devitalized tissue, are often present in cases of bacterial myositis. Bacterial causes are categorized by clinical presentation, anatomic location, and causative organisms into the categories of pyomyositis, psoas abscess, Staphylococcus aureus myositis, group A streptococcal necrotizing myositis, group B streptococcal myositis, clostridial gas gangrene, and nonclostridial myositis. Fungal myositis is rare and usually occurs among immunocompromised hosts. Parasitic myositis is most commonly a result of trichinosis or cystericercosis, but other protozoa or helminths may be involved. A parasitic cause of myositis is suggested by the travel history and presence of eosinophilia. Viruses may cause diffuse muscle involvement with clinical manifestations, such as benign acute myositis (most commonly due to influenza virus), pleurodynia (coxsackievirus B), acute rhabdomyolysis, or an immune-mediated polymyositis. The diagnosis of myositis is suggested by the clinical picture and radiologic imaging, and the etiologic agent is confirmed by microbiologic or serologic testing. Therapy is based on the clinical presentation and the underlying pathogen.

Gluteal pyomyositis in a non-tropical region as a rare cause of sciatic nerve compression: a case report

INTRODUCTION

Pyomyositis, or isolated abscess formation within a skeletal muscle, is a relatively common condition in tropical climates but it is only encountered rarely in temperate zones.

CASE PRESENTATION

We present a case of non-tropical pyomyositis of the gluteal muscle in a 26-year-old, previously healthy man from the United Kingdom, who initially presented with sciatica-like symptoms which began 3 days after a mosquito bite on his nose, which had become infected and discharged pus.

CONCLUSION

Gluteal pyomyositis involving the sciatic nerve may initially present as radiculopathy. Mosquito bites may have been the source of transient bacteraemia that contributed to muscle suppuration in this patient. This may explain, at least in part, the increased incidence of pyomyositis in healthy individuals living in tropical regions.

Primary pyomyositis of the paraspinal muscles: a case report and literature review

A case of non-tropical pyomyositis in a healthy, adolescent, 13-year-old boy, affecting the paraspinal muscles is presented. Computerised axial tomography scan (CT scan) of the spine provided valuable information on the nature, extent of the disease and helped to plan successful surgical management. None of the reported cases of such severity of paraspinal pyomyositis had involvement of quadratus lumborum muscle or compression on retroperitoneal organ as in our case.

Primary pyomyositis in children: a retrospective analysis of 11 cases

This study was undertaken to review our approach to diagnosis and treatment in a series of 11 patients (mean age 8.2 years) with primary pyomyositis, who had neither an underlying disease nor a compromised immune system. Nine of the children had positive blood cultures, Staphylococcus aureus (eight) and Streptococcus group A (one). The sites of infection were iliopsoas (four), obturator (two), hip adductors (two), levator scapula (one), thoracolumbar paraspinal (one) and gastrocnemius (one) muscles. Antibiotic treatment was initially intravenous, followed by oral administration. Of five patients with evidence of abscess formation, three underwent percutaneous drainage, whereas two required open surgical drainage. The infection resolved completely without any sequela in 10 children. One patient who developed acute compartment syndrome showed late signs of osteonecrosis of the tibial shaft segment.

Non-Clostridial Gas Gangrene of the Neck and Mediastinum

Herein we report a case of gas gangrene of the neck and mediastinum in a poorly managed Type II diabetic with concomitant chronic renal failure and a recent history of mucormycosis. Despite the burden of co-morbidities and the gravity of the illness, the patient was successfully treated and remained free of complications in the long term.

Les abcès pyogènes secondaires du psoas : à propos de six cas et revue de la littérature

PURPOSE

Psoas abscess is a rare disease in developed countries. Its diagnosis is difficult and any delay could lead to a worsen prognosis. The aim of this study is to determine the best diagnostic and therapeutic practices.

METHODS

A retrospective study of psoas abscess that occurred during six months was performed.

RESULTS

Six cases of secondary psoas abscess are reported. They were associated with spondylodiscitis in three cases, arthritis and gynaecologic infection in the three remaining cases. Anatomic diagnosis was performed by tomodensitometry. Microbiologic diagnosis was obtained by blood culture or direct puncture of the abscess. Antibiotics were associated with percutaneous drainage in two cases, with simple puncture in one case, and with surgery in one case. A local improvement w observed in all cases. The oldest patients presented the worst complications which were not directly caused by the abscess.

CONCLUSION

Physicians must be aware of psoas abscess because of their increasing incidence. Despite the fact that digestive pathologies are the main cause of secondary psoas abscess, bone infections, particularly spine infections, should be taken into consideration. Tomodensitometry guided puncture or percutaneous drainage are of diagnostic and therapeutic interest. Infectious samples must be taken before starting antibiotics, which have to be efficient against Gram negative bacillus, anaerobes and Staphylococcus aureus. Surgery must be quickly performed when the primary infection localisation need it, in case of voluminous abscess or when antibiotics and drainage are inefficient.