Increasing incidence of iliopsoas abscesses with MRSA as a predominant pathogen

Clinical Characteristics and In-Hospital Outcomes in Patients with Iliopsoas Abscess: A Multicenter Study

(1) Background: Iliopsoas abscess (IPA) is usually overlooked due to its nonspecific symptoms and signs. The resulting delayed diagnosis and treatment can increase morbidity and mortality. The purpose of the present study was to identify the risk factors for the unfavorable outcomes associated with IPA. (2) Methods: We included patients who presented to the emergency department and were diagnosed with IPA. The primary outcome was in-hospital mortality. Variables were compared, and the associated factors were examined with Cox proportional hazards model. (3) Results: Of the 176 patients enrolled, IPA was of primary origin in 50 patients (28.4%) and of secondary origin in 126 (71.6%). Skeletal origin was the most common source of secondary IPA (n = 92, 52.3%). The most common pathogens were Gram-positive cocci. Eighty-eight (50%) patients underwent percutaneous drainage, 32 (18.2%) patients underwent surgical debridement, and 56 (31.8%) patients received antibiotics. Multivariate analyses indicated that age > 65 (year) (HR = 5.12; CI 1.03-25.53; p = 0.046), congestive heart failure (HR = 5.13; CI 1.29-20.45; p = 0.021), and platelet < 150 (103/μL) (HR = 9.26; CI 2.59-33.09; p = 0.001) were significant independent predictors of in-hospital mortality in Model A, while the predictors in Model B included age > 65 (year) (HR = 5.12; CI 1.03-25.53; p = 0.046) and septic shock (HR = 61.90; CI 7.37-519.46; p < 0.001). (4) Conclusions: IPA is a medical emergency. Our study reported that patients with advanced age, congestive heart failure, thrombocytopenia, or septic shock had a significantly higher risk of mortality, and the recognition of the associated factors may aid in risk stratification and the determination of the optimal treatment plan for IPA patients.

Epidural phlegmon and iliopsoas abscess caused by Salmonella enterica bacteremia: A case report

INTRODUCTION AND IMPORTANCE

Iliopsoas abscesses (IPA) are rare and typically present with a non-specific triad of fever, back pain, and antalgic gait. Staphylococcus aureus is the organism responsible for nearly 90 % of IPA cases. We present a case of primary IPA with progression to osteomyelitis and discitis due to Salmonella enterica bacteremia, an exceedingly rare etiology occurring in an otherwise healthy individual.

CASE PRESENTATION

This patient presented with fever, back pain, and hip pain. Initial imaging and laboratory workup did not reveal any source of infection. He became septic within 72 h of admission, and blood cultures were confirmed as Salmonella enterica. However, the etiology of the infection remained unclear. Computed Tomography (CT) imaging revealed a right-sided psoas abscess measuring 7 mm × 7 mm and an epidural phlegmon. He was discharged home with intravenous ceftriaxone and levofloxacin. However, the patient was readmitted due to L2-L3 osteomyelitis and discitis with an eccentric disc bulge causing compression of the right L3 nerve root and neutropenia.

CLINICAL DISCUSSION

This case in unique in the fact that this occurred in a healthy patient with no significant risk factors or exposure to this bacteria. Additionally, this case highlights the rapid progression of IPA and the spread to adjacent spinal structures with the potential to cause nerve compression with successful medical management.

CONCLUSION

Salmonella enterica is rare cause of iliopsoas abscess. This case emphasizes the importance of including iliopsoas abscesses as a differential diagnosis in patients with a high index of clinical suspicion.

Characteristics and Outcomes of Psoas Abscess: Experience From a Tertiary Care Center in North India

Background

Psoas abscess (PA) is an uncommon disease involving infection of the psoas muscle with abscess formation. The evidence concerning clinical and diagnostic characteristics of PA and its outcomes is limited. The literature is heterogenous, with varying presentations and outcomes in different regions worldwide. We present a retrospective analysis of the clinical, radiological, and laboratory characteristics of PA, its management, and outcomes from a tertiary care center in North India.

Methodology

We reviewed the clinical records of confirmed cases of PA treated in our institute from January 2016 to December 2020 with a minimum follow-up of one year. Further, we performed a descriptive analysis of demographic characteristics, clinical features, laboratory parameters, radiological investigations, the basis of diagnosis confirmation, causative microorganisms, definitive management, treatment outcomes, and complications.

Results

We reviewed 33 cases with a mean age of 29.9 ± 16.8 years. Overall, 48.4% of PAs were right-sided, and 24.2% were bilateral. Abdominal discomfort was the most common presenting symptom. Blood laboratory parameters were mostly within the near-normal range except for the elevated erythrocyte sedimentation rate, C-reactive protein, and neutrophil-to-lymphocyte ratio. Ultrasonography was the most commonly performed radiological investigation and was the basis of diagnosis confirmation. Mycobacterium tuberculosis was the most common causative microorganism. Most patients required percutaneous drainage, and around one-fourth required open drainage. All patients had symptomatic as well as radiological improvement and no major complications.

Conclusions

Tuberculosis is the most prevalent cause of PA in the North Indian population. Most patients respond well to the less invasive treatment with percutaneous therapeutic drainage and antitubercular drugs, with few patients requiring open drainage. However, tissue diagnosis may remain inconclusive in a few patients, and antitubercular treatment may need to be initiated based on the clinicoradiological evaluation. Nevertheless, the rate of complications is low, with nil mortality probably related to the mild-to-moderate disease course of tuberculosis.

Development of an Iliacus Muscle Abscess after School Exercise in a 17-Year-Old Female Student

Primary psoas abscess is due largely to hematogenous or lymphatic spread under immunocompromised conditions, whereas secondary psoas abscess is due largely to direct spread from adjacent infected structures. Trauma or hematoma within the muscle may predispose to the development of a primary abscess, especially if infection is present prior to injury, despite the absence of previous signs or symptoms of infection. This report describes a 17-year-old female high school student who developed an abscess within her iliacus muscle due to methicillin-susceptible <i>Staphylococcus aureus</i> after running 3 km on a hill as a school exercise. She was positive for antinuclear antibody and had had atopic dermatitis, suggesting that these factors, as well as exercise-related minor trauma or hematoma within the muscle, may have predisposed to abscess formation. She was treated with appropriate antibiotics and surgical drainage, resulting in recovery after 4 weeks.

Clinical features, management, and outcome of iliopsoas abscess associated with cardiovascular disorders: a hospital-based observational case series study

BACKGROUND

Iliopsoas abscess (IPA) is a rare clinical entity and is difficult to diagnose due to its insidious onset and nonspecific symptoms. The association between IPA and cardiovascular disorders (CVD) has been rarely reported. Computed tomographic (CT) scan can provide a definitive diagnosis of IPA and associated foci of adjacent structures. IPA is a life-threatening condition, especially when associated with CVD.

MATERIALS AND METHODS

We conducted a hospital-based observational study of IPA associated with CVD. Data were collected from the electronic clinical database of Taichung Veterans General Hospital (1520-bed tertiary referral hospital in central Taiwan) between July 2007 and December 2017. The diagnosis of IPA associated with CVD was confirmed by classical findings on CT and transesophageal echocardiography with compatible clinical presentation and cultures from pus/tissue and blood.

RESULTS

Fifteen patients of IPA associated with CVD were studied. They included 12 males (80%) and 3 females (20%), with a mean age 63.2 ± 16.9 years (31-85 years). CVD included stent-graft/endograft infection of abdominal aortic aneurysm (AAA) (40%), primary mycotic AAA (33.3%), and infective endocarditis (26.7%). Staphylococcus aureus is the most common microorganism in pus/tissue cultures (n = 3, 37.5%) and in blood cultures (n = 6, 40%). The average length of hospital stay was 33.1 ± 20.5 days (range, 3-81 days; median, 33 days). Hospital stay lasted 42.6 ± 19.2 days in the survival group and 19.0 ± 14.1 days (P = 0.018) in the non-survival group. Incidence of patients staying in the intensive care unit (ICU) with intubation > 3 days was 33% in the survival group and 100% (P = 0.028) in the non-survival group. Intra-hospital mortality rate was 40%. Poor prognostic factors in the non-survival group were hypoalbuminemia, hyponatremia, involved disc/vertebral body and/or epidural abscess, and ICU stay with intubation > 3 days. Cumulative survival rate was 25% under conservative treatments and 66.3% under aggressive treatments (P = 0.038).

CONCLUSION

Due to high mortality rates, clinicians should keep a high suspicion index for IPA associated with CVD through clinical presentation, physical examination, and imaging study. Timely empiric antibiotics for common bacteria, drainage for IPA, endovascular repair, or vascular reconstruction by graft replacement or bypass with intensive care should be mandatory to shorten the hospital stay, reduce medical costs, and lower mortality rate.

Fatal case of ST8/SCCmecIVl community-associated methicillin-resistant Staphylococcus aureus infection in Japan

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) with ST8/SCCmecIV threatens human health. However, its pathogenesis remains unclear. ST8 CA-MRSA (CA-MRSA/J) with SCCmecIVl, which carries the large LPXTG-motif-containing putative adhesin gene, spj, has emerged in Japan. We present the first reported case of death from CA-MRSA/J. The patient was a 64-year-old woman with iliopsoas abscesses complicated by septic pulmonary embolism and multiorgan abscesses. Vancomycin, arbekacin, daptomycin and rifampicin were ineffective. CA-MRSA/J was resistant to erythromycin, clindamycin and antiseptics and was invasive in a HEp-2 cell assay, in contrast to skin-derived villous-adherent CA-MRSA/J. This suggests the strongly invasive pathotype of CA-MRSA/J.

Rare Case of Iliopsoas Abscess Secondary to Mucinous Adenocarcinoma of the Colon: A Case Report

Introduction

Iliopsoas abscess (IPA) has varied clinical symptomatology and various clinical disorders may mimic it. Tuberculosis of spine is the most common source of secondary IPA in the developing countries. However, IPA may be rarely caused by colon cancer which is the most common gastrointestinal malignancy. A mixed culture gives an indication of gastrointestinal or genitourinary etiology. We present here, a rare case of an 86-year-old patient with IPA secondary to adenocarcinoma of colon.

Case Report

An 86-year-old female presented with pain in the right thigh in February 2014. Computed tomography (CT) scan and magnetic resonance imaging (MRI) of the abdomen confirmed the clinical suspicion of right IPA which was drained surgically. Intraoperatively, mucinous material was noted, emerging from a small opening in a rounded structure located lateral to the psoas muscle, which could not be identified. On post-operative day 2, the right flank swelling recurred. Culture reports showed a polymicrobial infection with viridans group Streptococci and Pseudomonas aeruginosa. The abscess was re-explored and biopsy of the opening was taken. Histopathology of the tissue sample revealed metastatic cells of a mucin-secreting adenocarcinoma that had infiltrated the psoas muscle with a secondary pyogenic abscess. On reviewing the CT scan, there was a suspicion that the abscess was communicating with a tumor in the colon. No further active intervention was done for the tumor in view of advanced age and stage of tumor. The patient had significant pain relief and was able to resume walking. The infection resolved with 6 weeks of oral linezolid and ciprofloxacin. The patient died 8 months later secondary to metastasis.

Conclusion

Although the diagnosis of IPA does not pose problems, diagnosing secondary IPA requires a high index of clinical suspicion. A Gram-negative culture must raise the suspicion of gastrointestinal or genitourinary pathology. Colon carcinoma, although extremely rare, can lead to secondary IPA. CT and MRI though extremely useful, may not pick up the pathology and a definitive diagnosis of colon neoplasia perforating into the psoas muscle may be evident only intraoperatively. Atypical presentation may delay the diagnosis of colon cancer and subsequently result in higher morbidity and mortality.

Percutaneous drainage of psoas and iliopsoas muscle abscesses with a one-step technique under real-time computed tomography fluoroscopic guidance

PURPOSE

To evaluate the utility and safety of drainage catheter installation for psoas/iliopsoas muscle abscesses using a one-step technique under the guidance of real-time computed tomography (CT) fluoroscopy.

MATERIALS AND METHODS

Ten psoas or iliopsoas muscle abscesses in 7 patients that were treated with percutaneous drainage were included in this study. All drainage procedures were carried out using a one-step technique under real-time CT fluoroscopic guidance.

RESULTS

The drainage catheter insertion was performed successfully with the one-step technique in all lesions. Improvements in the patients' symptoms and blood test results were seen after the drainage procedure in all cases. In addition, postoperative CT scans demonstrated that the abscesses had reduced in size or disappeared in all but one patient, who was transferred to another institution while the drainage catheter was still in place. No major complications were seen in any case.

CONCLUSION

The one-step procedure is simple to perform. The percutaneous drainage of psoas or iliopsoas muscle abscesses with the one-step technique under real-time CT fluoroscopic guidance is accurate and safe. Moreover, compared with the two-step technique the one-step procedure results in a shorter drainage procedure and exposes the patient and operator to lower amounts of radiation. J. Med. Invest. 63: 323-327, August, 2016.

Bilateral primary psoas abscesses due to methicillin-resistant Staphylococcus aureus in a neutropenic patient: a case report

Background

Pyogenic abscess of psoas muscles is a rare condition. Psoas abscess due to methicillin-resistant Staphylococcus aureus is an emerging and rare infection and so far the related data are scarce.

Case presentation

We report the rare case of primary and bilateral large psoas abscesses due to methicillin-resistant Staphylococcus aureus in a 54-year-old Arab Jordanian woman with breast cancer who had neutropenia after starting chemotherapy. She was diagnosed 50 days after onset of symptoms. However, despite this delay in diagnosis and the large size of the abscesses, she had a full recovery. She was treated with antibiotics and percutaneous drainage and was doing very well at a follow up of 18 months.

Conclusions

Psoas abscess due to methicillin-resistant Staphylococcus aureus might have insidious presentation with extensive disease especially in immunocompromised patients. However, it can be managed effectively with percutaneous catheter drainage and appropriate antibiotic therapy.

Mycotic Abdominal Pseudoaneurysm due to Psoas Abscess after Spinal Fusion

A 36-year-old man, who had undergone thoracoscopic anterior spinal fusion using the plate system and posterior screw fusion three months previously, presented to our hospital with left flank pain and fever. Computed tomography indicated the presence of a psoas muscle abscess. However, after two days of percutaneous catheter drainage, a mycotic abdominal aortic pseudoaneurysm was detected via computed tomography. We performed in situ revascularization using a prosthetic graft with omental wrapping. Methicillin-resistant Staphylococcus aureus was identified on blood and pus culture, and systemic vancomycin was administered for one month. Although the abscess recurred, it was successfully treated with percutaneous catheter drainage and systemic vancomycin administration for three months, without the need for instrumentation removal. The patient remained asymptomatic throughout two years of follow-up.

Selective in vivo and in vitro activities of 3,3'-4-nitrobenzylidene-bis-4-hydroxycoumarin against methicillin-resistant Staphylococcus aureus by inhibition of DNA polymerase III

As the persistent resistance of Staphylococcus aureus to available antibiotics is associated with high infection incidence, mortality rate and treatment cost, novel antibacterial agents with innovative therapeutic targets must be developed. 3,3′-(4-Nitrobenzylidene)-bis-(4-hydroxycoumarin) (NBH), a dicoumarin derivative, was reported to exert antibacterial activity. This study investigated the underlying mechanisms of in vivo and in vitro activities of NBH against S. aureus. NBH exerted bactericidal effects against the tested S. aureus and Staphylococcus epidermidis strains in vitro, with low cytotoxicity and resistance and high plasma stability. NBH also exhibited therapeutic effects in vivo on septicaemic mice. Results of molecular docking and analysis on morphological change, DNA production and polymerase inhibition suggested that DNA polymerase could be the target of NBH. These findings indicated that dicoumarin derivatives, which interfere with DNA replication, could be developed as a potential agent against S. aureus, particularly methicillin-resistant strains.

Virulence gene and expression analysis of community-associated methicillin-resistant Staphylococcus aureus causing iliopsoas abscess and discitis with thrombocytopenia

Iliopsoas abscesses (IPAs) from methicillin-resistant Staphylococcus aureus (MRSA) are rare; however, IPAs from community-associated MRSA (CA-MRSA) may be increasing. In Japan, we previously described an adolescent athlete case of Panton-Valentine leukocidin (PVL)-positive ST30 CA-MRSA (strain NN12). In this study, we describe an IPA and discitis case from a variant of the successful PVL-negative CA-MRSA clone (ST8 CA-MRSA/J) in Japan. The patient was a 62-year-old man with intractable eczema, who had been diagnosed with IPAs and discitis (L1-L2). CA-MRSA (strain NN55) was isolated from blood, pus, and joint fluid. The invasive infections seemed to have originated in his intractable eczema, and the characteristics of this case, systemic myalgia and marked thrombocytopenia, seemed to have been caused by an exotoxin. Molecular genetic analysis revealed that NN55 possessed genotype ST8/spa606(t1767)/agr1/CoaIII and SCCmecIV of a novel subtype (encoding new cell-wall-anchored surface protein/J [CWASP/J]), exhibited enhanced expression of the cytolytic peptide genes, psmα and hld, and was resistant to gentamicin (caused by aacA-aphD), similar to ST8 CA-MRSA/J; however, NN55 lacked pathogenicity island SaPIj50 [carrying tst, encoding toxic shock syndrome toxin-1 (TSST-1)] of ST8 CA-MRSA/J, suggesting a variant (ST8 CA-MRSA/Jv). Strains NN12 and NN55 both caused bacteremia, IPAs, and adjacent musculoskeletal infections, preceded by intractable skin infections, and possessed high potential for adherence and enhanced expression of psmα and hld. The data suggest the role of a combination of CA-MRSA adhesin/cytolytic peptides (not PVL or TSST-1) in the pathogenesis of IPAs (and perhaps of systemic myalgia and marked thrombocytopenia).