Skin and Soft Tissue Infections in the Emergency Department

Imaging of MSK infections in the ER

Musculoskeletal infections in the ER are not an uncommon presentation. The clinical context is critical in determining the suspicion for infection and degree of tissue involvement which can involve all layers from the skin to bones. The location, extent, and severity of clinically suspected infection directly relate to the type of imaging performed. Uncomplicated cellulitis typically does not require any imaging. Localized and superficial infections can mostly be evaluated with ultrasound. If there is a diffuse site (an entire extremity) or suspected deeper involvement (muscle/deep fascia), then CT is accurate in diagnosing, widely available, and performed quickly. With potential osseous involvement, MRI is the gold standard for diagnosing acute osteomyelitis; however, it has the drawbacks of longer scan times, artifacts including patient motion, and limited availability.

Clinical Impact of Staphylococcus aureus Skin and Soft Tissue Infections

The pathogenic bacterium Staphylococcus aureus is the most common pathogen isolated in skin-and-soft-tissue infections (SSTIs) in the United States. Most S. aureus SSTIs are caused by the epidemic clone USA300 in the USA. These infections can be serious; in 2019, SSTIs with S. aureus were associated with an all-cause, age-standardized mortality rate of 0.5 globally. Clinical presentations of S. aureus SSTIs vary from superficial infections with local symptoms to monomicrobial necrotizing fasciitis, which can cause systemic manifestations and may lead to serious complications or death. In order to cause skin infections, S. aureus employs a host of virulence factors including cytolytic proteins, superantigenic factors, cell wall-anchored proteins, and molecules used for immune evasion. The immune response to S. aureus SSTIs involves initial responders such as keratinocytes and neutrophils, which are supported by dendritic cells and T-lymphocytes later during infection. Treatment for S. aureus SSTIs is usually oral therapy, with parenteral therapy reserved for severe presentations; it ranges from cephalosporins and penicillin agents such as oxacillin, which is generally used for methicillin-sensitive S. aureus (MSSA), to vancomycin for methicillin-resistant S. aureus (MRSA). Treatment challenges include adverse effects, risk for Clostridioides difficile infection, and potential for antibiotic resistance.

Improving Quality Metrics with a Day-only Skin Abscess Protocol: Experience from Australia

BACKGROUND

Skin abscesses are a common emergency presentation often requiring incision and drainage; however, issues with theatre access lead to delays in management and high costs. The long-term impact in a tertiary centre of a standardised day-only protocol is unknown. The aim was to evaluate the impact of day-only skin abscess protocol (DOSAP) for emergency surgery of skin abscesses in a tertiary institution in Australia and to provide a blueprint for other institutions.

METHODS

A retrospective cohort study analysed several time periods: Period A (July 2014 to 2015, n = 201) pre-DOSAP implementation, Period B (July 2016 to 2017, n = 259) post-DOSAP, and Period C (July 2018 to 2022, n = 1,625) prospectively analysed four 12-month periods to assess long-term utilisation of DOSAP. Primary outcomes were length of stay and delay to theatre. Secondary outcome measures included theatre start time, representation rates and total costs. Statistical analysis using nonparametric methods was used to analyse the data.

RESULTS

There was a significant decrease in ward length of stay (1.25 days vs. 0.65 days, P < 0.0001), delay to theatre (0.81 days vs. 0.44 days, P < 0.0001) and theatre start time before 10AM (44 cases vs. 96 cases, P < 0.0001) after implementation of DOSAP. There was a significant decrease in median cost of admission of $711.74 after accounting for inflation. Period C reported 1,006 abscess presentations successfully managed by DOSAP over the four-year period.

CONCLUSION

Our study demonstrates the successful implementation of DOSAP in an Australian tertiary centre. The ongoing utilisation of the protocol demonstrates the ease of applicability.

Spectrum of imaging findings in soft-tissue necrosis

Soft tissue necrosis can occur at different tissue levels, with numerous underlying causes. In this pictorial review, we highlight myonecrosis, and its accompanying stages, fat necrosis, devitalized soft tissue seen with infection, and necrotizing soft tissue infections. Imaging examples are provided with each entity.

Risk factors for non-invasive (skin and soft tissue) and invasive Staphylococcus aureus infections among children and adults living in southeastern USA: a retrospective cohort study

Objective

To characterise individual and area-level risks associated with invasive or skin and soft tissue (SSTIs) Staphylococcus aureus infections comparing methicillin-resistant S. aureus (MRSA) with methicillin-sensitive S. aureus (MSSA); and highlight differences between children and adults.

Setting

A population-based study from 21 reporting laboratories located in Georgia Health District 3 (HD3), an eight-county catchment area around metro Atlanta.

Participants

A case is a resident of HD3 from whom S. aureus had been isolated in 2017.

Primary outcome

Culture-confirmed S. aureus infections, classified as skin and soft tissue (proxy for non-invasive) or invasive, by methicillin-sensitivity status.

Results

The incidence of SSTIs was 19.7/100 000, compared with 5.2/100 000 for invasive infections. Adults experienced higher rates of SSTIs (22.3/100 000) and invasive infections (6.7/100 000) compared with children with SSTIs (13.0/100 000) and invasive infections (1.3/100 000). Risks of MRSA versus MSSA SSTIs were similar for children and adults. Black individuals with SSTIs were more likely to have MRSA than white individuals (children (OR 1.43, 95% CI 1.16 to 1.76); adults (OR 1.24, 95% CI 1.08 to 1.42)). Adults with invasive MRSA were more likely to be black (adjusted OR 1.69, 95% CI 1.25 to 2.29) compared with those with invasive MSSA. Children with invasive MRSA were more likely from a racial-ethnic concentrated area (OR 4.66, 95% CI 1.85 to 11.71). Hotspots of MRSA were found in crowded areas with higher rates of black populations.

Conclusions

The risk of MRSA infections in children and adults can be defined by unique area-level sociodemographic characteristics which were distinct for those areas associated with MSSA infections. Place-based risks of MRSA or MSSA can be used to develop target public health interventions to decrease transmission and incidence.

A Case of Forearm Soft Tissue Infection Caused by Hypervirulent K. pneumoniae in an Otherwise Healthy 24-Year-Old Woman

In recent years, hypervirulent Klebsiella pneumoniae (hvKp) has received greater attention. It mainly infects diabetic patients and typically causes a hepatic abscess. Here, we report a case of hvKp that caused forearm muscle and soft tissue infection in addition to bacteremia, hepatic and pulmonary abscess, and hyperglycemia. The patient’s condition stabilized after comprehensive treatment. She eventually recovered and was discharged after several debridement and flap operations. At 9 months of follow-up, no signs of infectious recurrence were noted, and the hyperglycemia resolved. Here, we detail important clinical features of a severe hvKp case diagnosed in an otherwise healthy individual. This report underscores the potential of hvKp to cause deep tissue infection and present with clinical symptoms similar to gas gangrene. Symptom onset in the setting of hvKp infection is usually gradual and misdiagnosis is common. The diagnosis of hvKp should be routinely considered in the clinical setting, and be strongly suspected when presenting with characteristic epidemiological, clinical and laboratory features. Although diabetes is a predisposing factor to hvKp infection, hyperglycemia appeared to manifest as a consequence of hvKp infection in this patient.

Emergency department utilization for impetigo among the pediatric population: A retrospective study of the national emergency department sample 2013-2015

BACKGROUND

Despite the large burden of impetigo in childhood and high frequency of pediatric emergency department (ED) visits for skin conditions, limited information exists on the use of EDs for impetigo among US children.

OBJECTIVE

Our study aimed to generate national estimates of ED utilization and to identify sociodemographic predictors of impetigo-related ED visits.

METHODS

This was a retrospective, cross-sectional study of children ages 1-17 presenting to EDs with a primary diagnosis of impetigo using years 2013-2015 of the Nationwide Emergency Department Sample.

RESULTS

Impetigo accounted for 163 909 of the 71 488, 511 pediatric ED visits and was the fourth most common presenting skin diagnosis. Controlling for sociodemographic factors, patients presenting to the ED with impetigo were most likely to be 6-11 years old, male, and from lower-income quartiles. Patients were most likely to be uninsured and most likely to present on weekends in the summer.

CONCLUSION

This study provided national-level estimates of ED use for impetigo among US children. Ultimately, the identification of factors associated with increased ED utilization may help in developing targeted interventions to reduce the use of emergency care for impetigo.

Anti-MRSA Cephalosporin versus Vancomycin-Based Treatment for Acute Bacterial Skin and Skin Structure Infection: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

This systematic review and meta-analysis of randomized controlled trials (RCTs) compared the clinical efficacy and safety of anti-MRSA cephalosporin and vancomycin-based treatment in treating acute bacterial skin and skin structure infections (ABSSSIs). PubMed, Embase, Cochrane Central Register of Controlled Trials, Turning Research into Practice, and ClinicalTrials.gov databases were searched for relevant articles from inception to 15 June 2020. RCTs comparing the clinical efficacy and safety of anti-MRSA cephalosporin with those of vancomycin-based regimens in treating adult patients with ABSSSIs were included. The primary and secondary outcomes were clinical response at the test-of-cure assessments and risk of adverse events (AEs), respectively. Eight RCTs were enrolled. The clinical response rate was not significantly different between anti-MRSA cephalosporin and vancomycin-based treatments (odds ratio [OR], 1.05; 95% CI, 0.90–1.23; I² = 0%). Except for major cutaneous abscesses in which anti-MRSA cephalosporin-based treatment was associated with a lower clinical response rate than vancomycin-based treatment (OR, 0.62; 95% CI, 0.40–0.97; I² = 0%), other subgroup analyses according to the type of cephalosporin (ceftaroline or ceftobiprole), type of infection, and different pathogens did not show significant differences in clinical response. Anti-MRSA cephalosporin-based treatment was only associated with a higher risk of nausea than vancomycin-based treatment (OR, 1.41; 95% CI, 1.07–1.85; I² = 0%). In treating ABSSSIs, the clinical efficacy of anti-MRSA cephalosporin is comparable to that of vancomycin-based treatment, except in major cutaneous abscesses. In addition to nausea, anti-MRSA cephalosporin was as tolerable as vancomycin-based treatment.

Clinical efficacy and safety of ceftobiprole in the treatment of acute bacterial skin and skin structure infection: a systematic review and meta-analysis of randomized controlled trials

Objectives: To investigate the clinical efficacy and safety of ceftobiprole for acute bacterial skin and skin structure infections (ABSSSIs).Methods: PubMed, Web of Science, EBSO, Ovid Medline, ClinicalTrial.gov and Cochrane Library were searched until 25 December 2020. Only randomized controlled trials that compared the treatment efficacy of ceftobiprole with that of other antibiotics for adult patients with ABSSSIs were included in this meta-analysis.Results: The 3 RCTs involving 2291 adult patients with ABSSSIs were included. No significant difference in clinical success, as measured by the TOC, was observed between ceftobiprole and comparators among the intention-to-treat population (OR, 1.06; 95% CI, 0.85-1.33; I² = 0%) and clinical evaluable population (OR, 1.17; 95% CI, 0.76-1.79; I² = 17%). Ceftobiprole was associated with a similar risk of adverse events (AEs) to that of comparators.Conclusions: Ceftobiprole can achieve similar clinical and microbiological responses as alternative antibiotics in patients with ABSSSIs. In addition, ceftobiprole shares a similar safety profile to comparators.

Bacterial Antifouling Characteristics of Helicene-Graphene Films

Herein, we describe interfacially-assembled [7]helicene films that were deposited on graphene monolayer using the Langmuir-Schaefer deposition by utilizing the interactions of nonplanar (helicene) and planar (graphene) π–π interactions as functional antifouling coatings. Bacterial adhesion of Staphylococcus aureus on helicene—graphene films was noticeably lower than that on bare graphene, up to 96.8% reductions in bacterial adhesion. The promising bacterial antifouling characteristics of helicene films was attributed to the unique molecular geometry of helicene, i.e., nano-helix, which can hinder the nanoscale bacterial docking processes on a surface. We envision that helicene—graphene films may eventually be used as protective coatings against bacterial antifouling on the electronic components of clinical and biomedical devices.

Host Defense Peptide-Mimicking Amphiphilic β-Peptide Polymer (Bu:DM) Exhibiting Anti-Biofilm, Immunomodulatory, and in Vivo Anti-Infective Activity

Therapeutic options to treat multidrug resistant bacteria, especially when present in biofilms, are limited due to their high levels of antibiotic resistance. Here, we report the anti-biofilm and immunomodulatory activities of the host defense peptide (HDP)-mimicking β-peptide polymer (20:80 Bu:DM) and investigated its activity in vivo. The polymer outperformed antibiotics in the removal and reduction of the viability of established biofilms, achieving a maximum activity of around 80% reduction in viability. Interestingly the polymer also exhibited HDP-like immunomodulation in inducing chemokines and anti-inflammatory cytokines and suppressing lipopolysaccharide-induced proinflammatory cytokines. When tested in a murine, high-density skin infection model using P. aeruginosa LESB58, the polymer was effective in diminishing abscess size and reducing bacterial load. This study demonstrates the dual functionality of HDP-mimicking β-peptide polymers in inhibiting biofilms and modulating innate immunity, as well as reducing tissue dermonecrosis.

A multifaceted intervention improves antibiotic stewardship for skin and soft tissues infections

OBJECTIVE

Assess the effectiveness of a multifaceted stewardship intervention to reduce frequency and duration of inappropriate antibiotic use for emergency department (ED) patients with skin and soft tissue infections (SSTI). We hypothesized the antibiotic stewardship program would reduce antibiotic duration and improve guideline adherence in discharged SSTI patients.

DESIGN

Nonrandomized controlled trial.

SETTING

Academic EDs (intervention site and control site).

PATIENTS OR PARTICIPANTS

Attending physicians and nurse practitioners at participating EDs.

INTERVENTION(S)

Education regarding guideline-based treatment of SSTI, tests of antimicrobial treatment of SSTI, implementation of a clinical treatment algorithm and order set in the electronic health record, and ED clinicians' audit and feedback.

RESULTS

We examined 583 SSTIs. At the intervention site, clinician adherence to guidelines improved from 41% to 51% (aOR = 2.13 [95% CI: 1.20-3.79]). At the control site, there were no changes in adherence during the "intervention" period (aOR = 1.17 [0.65-2.12]). The between-site comparison of these during vs. pre-intervention odds ratios was not different (aOR = 1.82 [0.79-4.21]). Antibiotic duration decreased by 26% at the intervention site during the intervention compared to pre-intervention (Adjusted Geometric Mean Ratio [95% CI] = 0.74 [0.66-0.84]). Adherence was inversely associated with SSTI severity (severe vs mild; adjusted OR 0.42 [0.20-0.89]) and purulence (0.32 [0.21-0.47]). Mean antibiotic prescription duration was 1.95 days shorter (95% CI: 1.54-2.33) in the time period following the intervention than pre-intervention period.

CONCLUSIONS

A multifaceted intervention resulted in modest improvement in adherence to guidelines compared to a control site, driven by treatment duration reductions.

Severe bacterial skin infections

The severe bacterial diseases discussed herein are those that present dermatological lesions as their initial manifestations, for which the dermatologist is often called upon to give an opinion or is even the first to examine the patient. This review focuses on those that evolve with skin necrosis during their natural history, that is, necrotizing fasciitis, Fournier gangrene, and ecthyma gangrenosum. Notice that the more descriptive terminology was adopted; each disease was individualized, rather than being referred by the generic term "necrotizing soft tissue infections". Due to their relevance and increasing frequency, infections by methicillin-resistant Staphylococcus aureus (MRSA) were also included, more specifically abscesses, furuncle, and carbuncle, and their potential etiologies by MRSA. This article focuses on the epidemiology, clinical dermatological manifestations, methods of diagnosis, and treatment of each of the diseases mentioned.

Necrotizing Fasciitis Complicating Transobturator Tape Operation

Midurethral slings (MUSs) have been used successfully for the last 20 years in the treatment of stress urinary incontinence and accepted as the gold standard surgical procedure. High success rates and minimal invasiveness of surgery are among the most important advantages, but sometimes serious complications can occur during or after surgery. Although serious complications are rare after widely performed transobturator tape (TOT) operation, awareness, early diagnosis, and aggressive management are essential as they can progress with serious morbidity and mortality. In order to reduce the infectious complications after MUS procedures, in addition to sterility of the operating theater and the operating equipment, the type of mesh used and the preparation of the surgical site are crucial. We aimed to pre-sent the successful management of a case of necrotizing fasciitis in a TOT patient.

International survey evaluating treatment of primary superficial skin abscesses

INTRODUCTION

Skin and soft-tissue infections (SSTI) present regularly as cutaneous abscesses which require surgical drainage. These abscesses often affect younger patients and interfere with their independency substantially. Existing guidelines display heterogeneous recommendations concerning surgical aftercare. Primary aim of this survey was to present a nomogram for standard abscess therapy based on international expert opinions.

METHOD

An online survey dealing with standard of care protocols for cutaneous abscesses concerning surgical treatment and aftercare was created. The survey was conducted in 2017 during two international conferences held in Switzerland.

RESULT

490 surgeons originating from 66 nations participated in this survey with the majority coming from Europe and Asia. Indication for surgery, operation type, and wound rinsing were answered homogeneously. Perioperative setting (45% sterile, 55% semi-sterile), anesthesia (45% local, 55% general), antibiotic therapy (38% always, 35% never, 27% other), irrigation fluid (54% sterile, 32% non-sterile, 14% antiseptic), irrigation frequency (55% once daily, 30% twice daily), and wound dressing (69% packing, 31% coverage) were heterogeneously answered topics.

CONCLUSION

Treatment and aftercare of simple primary skin abscesses are processed heterogeneously throughout the world. Focus should be on optimal patient focused treatment with minimal socio-economic impact. Future studies should focus on the validation of the different postoperative treatment options with the aim to develop a socio-economically accepted algorithm.

Accurate and quick predictor of necrotizing soft tissue infection: Usefulness of the LRINEC score and NSTI assessment score

OBJECTIVE

The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score is a diagnostic tool for necrotizing soft tissue infection (NSTI), which is validated and is considered to have high diagnostic value. However, some experts criticize LRINEC score for consisting of laboratory test results only.

METHODS

In this single-center retrospective study, we created a new scoring system (NSTI assessment score; NAS), which also incorporated vital signs as another diagnostic tool for NSTI using cases from our hospital and also evaluated diagnostic accuracy of LRINEC score. We identified NSTI predictors by comparing 24 NSTI patients and 80 non NSTI patients using uni- and multivariate logistic regression analysis, and created NAS based on odds ratio of variables which are statistically significant in the multivariate model.

RESULTS

We identified mean arterial pressure, C-reactive protein, hemoglobin, serum creatinine, and glucose as a predictor for NSTI. The maximum value of NAS was 11 points with the cut-off value of 6. Sensitivity, specificity, positive predictive value, and negative predictive value of the NAS for diagnosis of NSTI were 87.5%, 91.3%, 75.0%, and 96.1%, respectively. Area under the receiver operating characteristic curve was 0.926 (0.851-1.00) for the NAS and 0.903 (0.833-0.973) for the LRINEC score, and they were not statistically different (p = 0.167).

CONCLUSION

The NAS has high diagnostic accuracy in predicting NSTI, and is comparable with the LRINEC score. The NAS needs to be validated in other cohorts in the future.