A Comparative Phenotypic and Genomic Analysis of Methicillin-Resistant Staphylococcus aureus ST45 Isolates From Cellulitis and Osteomyelitis in Taiwan.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) sequence type (ST) 45 is a globally disseminated MRSA lineage. Herein, we investigated whether MRSA ST45 isolates from cellulitis and from osteomyelitis display distinctive phenotypic and genomic characteristics. METHODS: A total of 15 MRSA ST45 isolates from cellulitis (CL-MRSA; n = 6) or osteomyelitis (OM-MRSA; n = 9) were collected in a Taiwan hospital. These MRSA ST45 isolates were characterized for their antimicrobial susceptibility, biofilm-forming ability, cellular infectivity in vitro, and pathogenicity in vivo. Four CL-MRSA and 6 OM-MRSA ST45 isolates were selected for whole-genome sequencing (WGS). RESULTS: Antibiotic resistance tests showed that all OM-MRSA ST45 strains, but not CL-MRSA ST45 strains, were resistant to ciprofloxacin, levofloxacin, gentamicin, and doxycycline. Compared to the CL-MRSA ST45 isolates, the OM-MRSA ST45 isolates had stronger biofilm-forming ability and cellular infectivity and caused more severe disease in mice. WGS analysis revealed that these OM-MRSA ST45 isolates carry multiple common mutations or polymorphisms in genes associated with antibiotic resistance and virulence. Moreover, the transposable elements IS256 and IS257R2 were found only in the OM-MRSA ST45 isolates. CONCLUSIONS: The emergence and spread of the highly pathogenic and multidrug-resistant ST45 MRSAs identified from osteomyelitis may pose a serious threat on public health.

Doxycycline versus cephalexin treatment of presumed streptococcal skin and soft tissue infection among adults presenting to the emergency department.

Among 100 propensity score-matched emergency department patients receiving ≤14 days doxycycline versus cephalexin monotherapy for outpatient treatment of nonpurulent (presumed streptococcal) skin and soft tissue infection, a low rate of 14-day clinical failure was observed [6% each group; odds ratio (OR), 1.34 (0.21-8.69); P = 0.745], defined as hospital admission, i.v. antibiotic therapy, or change in oral antibiotic. Doxycycline may represent a reasonable therapeutic alternative for this indication in regions with low tetracycline resistance.

Periorbital necrotizing fasciitis: clinical perspectives on nine cases.

A multicenter review of Periorbital Necrotizing Fasciitis including nine cases, aged 41 to 82, mostly female, and mainly post-traumatic or idiopathic. Streptococcus pyogenes was the most frequent pathogen. Treatment involved debridement alongside antibiotic therapy in all cases. Two cases experienced toxic shock, with no fatalities. Visual outcomes varied from exenteration to preserved visual acuity with minimal aesthetic impact. Early detection and prompt intervention are paramount due to the significant risks associated with this condition, which may lead to severe complications ranging from vision loss to systemic decline or death.

Experience with dalbavancin use in various gram-positive infections within Aberdeen Royal Infirmary OPAT service.

PURPOSE: Dalbavancin, approved in 2014 for Gram-positive acute bacterial skin and skin structure infections (ABSSSI), has pharmacokinetics enabling treatment with one or two doses. Dalbavancin might be useful in outpatient parenteral antibiotic therapy (OPAT) of deep-seated infections, otherwise requiring inpatient admission. We documented our experience with pragmatic dalbavancin use to assess its effectiveness for varied indications, on- and off-label, as primary or sequential consolidation therapy. METHODS: Patients prescribed dalbavancin between 1 December 2021 and 1 October 2022 were screened for demographics of age, sex, Charlson comorbidity index (CCI), allergies, pathogens, doses of dalbavancin, other antibiotics administered and surgery. Where available, infection markers were recorded. The primary outcome was a cure at the end of treatment. Secondary outcomes included any adverse events and for those with treatment failures, response to salvage antibiotics. RESULTS: Sixty-seven per cent of patients were cured. Cure rates by indication were 93% for ABSSSI, 100% for bacteraemia, 90% for acute osteomyelitis, 0% for chronic osteomyelitis, 75% for native joint septic arthritis and 33% for prosthetic joint infection. Most bone and joint infections that were not cured did not have source control, and the goal of treatment was suppressive. Successful suppression rates were greater at 48% for chronic osteomyelitis and 66% for prosthetic joint infections. Adverse events occurred in 14 of 102 patients. CONCLUSION: This report adds to clinical experience with dalbavancin for off-label indications whilst further validating its role in ABSSSI. Dalbavancin as primary therapy in deep-seated infections merits investigation in formal clinical trials.

Quantitative analysis of the impact of infectious disease physicians on patients in the emergency department fast-track parenteral antibiotics program.

INTRODUCTION: The outpatient parenteral antibiotic therapy (OPAT) program of Vancouver General Hospital (VGH) was supervised by emergency physicians (EPs) until 2017 when infectious disease (ID) physicians began assisting in management. We designed a retrospective study to determine whether ID involvement led to improved outcomes. METHODS: This study analyzes the impact of ID involvement by comparing the mean days patients spent on OPAT with ID involvement versus EPs alone through a retrospective chart review. Secondary research objectives were to compare patient care decisions, e.g., antibiotic choice, tests ordered, and final diagnosis. RESULTS: There was no difference between the mean number of days on OPAT between physician types. Compared to historic patterns, patients seen in OPAT after increased ID consultation spent an average of 0.5 fewer days in the program. However, when grouped by the first day of ID assessment, the average total days in OPAT was closely aligned with the day of first ID assessment, implying that ID frequently discharged patients close to initial assessment. Patients seen by ID were less likely to return within one month of discharge compared to those not seen by ID. Secondary findings include ID physicians prescribing a greater range of antibiotics, providing more varied final diagnoses, prescribing antibiotics less frequently, as well as ordering more cultures, diagnostic imaging and specialist consults. DISCUSSION: The findings of this study support the hypothesis that ID involvement in OPAT programs leads to changes in care that may have beneficial outcomes for patients and the healthcare system.

Factors associated with cellulitis in lymphoedema of the arm - an international cross-sectional study (LIMPRINT).

BACKGROUND: Lymphoedema is a globally neglected health care problem and a common complication following breast cancer treatment. Lymphoedema is a well-known predisposing factor for cellulitis, but few have investigated the risk factors for cellulitis in this patient cohort on an international level. The aim of this study was to identify the frequency of cellulitis in patients with lymphoedema of the arm, including potential risk factors for cellulitis. METHODS: An international, multi-centre, cross-sectional study including patients with clinically assessed arm lymphoedema. The primary outcome was the incidence of cellulitis located to the arm with lymphoedema within the last 12 months, and its potential associated risk factors. The secondary outcome was life-time prevalence of cellulitis. Adults with clinically-assessed arm lymphoedema/chronic oedema (all causes) and able to give informed consent were included. End-of-life-patients or those judged as not in the patient's best interest were excluded. Both univariable and multivariable analysis were performed. RESULTS: A total of 2160 patients were included from Australia, Denmark, France, Ireland, Italy, Japan, Turkey and United Kingdom. Secondary lymphoedema was present in 98% of the patients; 95% of these were judged as related to cancer or its treatment. The lifetime prevalence of cellulitis was 22% and 1-year incidence 11%. Following multivariable analysis, factors associated with recent cellulitis were longer swelling duration and having poorly controlled lymphoedema. Compared to having lymphoedema less than 1 year, the risk increased with duration: 1-2 years (OR 2.15), 2-5 years (OR 2.86), 5-10 years (OR 3.15). Patients with well-controlled lymphoedema had a 46% lower risk of cellulitis (OR 0.54, 95% CI 0.39-0.73, p < 0.001). More advanced stages of lymphoedema were associated with cellulitis even after adjustment for swelling duration and control of swelling by logistic regression (stage II OR 5.44, stage III OR 9.13, p = 0.002), demonstrated in a subgroup analysis. CONCLUSION: Patients with advanced arm lymphoedema are at particular risk of developing cellulitis. Prevention of lymphoedema progression is crucial. The results lend towards a positive effect of having well-treated lymphoedema on the frequency of cellulitis.

Pediatric head and neck emergencies.

PURPOSE: Head and neck emergencies in children are frequent cause of visits to the hospital. Imaging plays a critical role in the management of these patients. This review article aims to familiarize radiologists with the common clinical presentations encountered, imaging characteristics of nontraumatic pediatric head and neck emergencies, and improve their ability to recognize associated complications as well as be aware of common mimics. METHODS: We researched our database for commonly encountered nontraumatic head and neck emergencies in children. A literature search was done to compare and complete the list of conditions to be discussed in this review. RESULTS: The review was organized according to anatomical location of the emergent condition. Relevant anatomy has been discussed along with clinical presentation, imaging characteristics and complications. We have presented common mimics with each set of disorders. Key imaging characteristics have been delineated using radiology images. CONCLUSION: Familiarity with the known complications of head and neck emergencies allows the radiologist to actively search for such findings, encourage early institution of appropriate therapy, and improve outcomes.

Aspergillus terreus panophthalmitis with orbital cellulitis.

An eleven year old male reported a ten-day history of unilateral pain, redness, and sudden loss of vision. Ophthalmic examination revealed panophthalmitis that did not respond to conventional intravenous antibiotics, and systemic deterioration raised suspicion of a fungal aetiology. However, the worsening of the ocular condition from panophthalmitis to orbital cellulitis upon commencement of amphotericin B suggests the presence of a fastidious microorganism. Aspergillus terreus was isolated from a vitreous tap sample and responded well to intravenous voriconazole, exhibiting a distinct antimicrobial susceptibility spectrum and emphasising its possible involvement in relatively healthy early adolescence. To the author's knowledge, panophthalmitis with orbital cellulitis in early adolescence, without prior ocular insult, paranasal sinus involvement, or immunocompromised status, has not been reported previously.

Recurrent cellulitis and bacteremia in a patient with Noonan syndrome: A case report.

A 28-year old Japanese man with Noonan syndrome (NS) presented to our emergency department with painful erythema of the trunk and lower extremities since the previous day. He had been diagnosed with protein-losing enteropathy (PLE) with intestinal lymphangiectasia at age 25 years, and undergone lymphaticovenular anastomosis (LVA) twice. Three episodes of cellulitis of both lower extremities had occurred in the past 2 years. Extensive cellulitis with sepsis was diagnosed and piperacillin/tazobactam was started, which was de-escalated to ceftriaxone. He was discharged after 13 days of antibiotic therapy. After discharge, low-dose trimethoprim-sulfamethoxazole (SMZ-TMP) was started as the primary prophylaxis, but three episodes of cellulitis occurred in the next year and were treated with other antibiotics. NS, an autosomal dominant disease known as a RASopathy, is caused by germline mutations in RAS-MAPK pathway genes. Lymphedema resulting from lymphatic abnormalities is a concomitant manifestation in 20 % of patients with NS, and can be a risk factor for cellulitis. Hypoalbuminemia and hypoglobulinemia associated with PLE facilitate infections such as cellulitis. As a treatment for lymphedema in the extremities, LVA has shown objective and subjective improvements in most patients, and some studies have also reported its efficacy for lymphedema in patients with NS. Targeted molecular therapy with mitogen-activated protein kinase enzyme (MEK) inhibitor is used in treatment of cancers with activation of the RAS/MAPK pathway. MEK inhibitors have recently been tried in patients with RASopathies and severe lymphatic disorders, and can lead to rapid resolution of symptoms.

Oral antimicrobial therapy for cellulitis versus outpatient parenteral antimicrobial therapy: a single-centre audit of cellulitis outcomes.

BACKGROUND: Cellulitis is a common acute skin and soft tissue infection that causes substantial morbidity and healthcare costs. AIMS: To audit the impact on cellulitis management, regimen tolerability and outcomes of switching from outpatient parenteral antimicrobial therapy (OPAT) using intravenous (i.v.) cefazolin once daily plus probenecid to oral beta-lactam therapy (OBLT) using oral flucloxacillin plus probenecid. METHODS: We undertook a retrospective audit on cellulitis management, regimen tolerability and outcomes at the Dunedin Public Hospital Emergency Department (ED) before and after a change of the local outpatient cellulitis treatment pathway from OPAT using i.v. cefazolin once daily plus probenecid to OBLT using oral flucloxacillin plus probenecid. RESULTS: OPAT was used in 97/123 (78.9%) patients with cellulitis before compared to 1/70 (1.4%) after the pathway change (odds ratio (OR), 0.04, P < 0.01). OBLT was used in 26/123 (21.1%) patients with cellulitis before and 69/70 (98.6%) after (OR, 218.8, P < 0.01). Antimicrobial change due to intolerance occurred in 4/123 (3.2%) patients with cellulitis before and 4/70 (5.7%) after (OR, 1.8, P, not significant (NS)) the pathway change. Inpatient admission within 28 days occurred in 15/123 (12.2%) cellulitis patients before and 9/70 (12.9%) after (OR, 1.1, P, NS) the pathway change. CONCLUSIONS: Implementation of a change in outpatient cellulitis treatment pathway resulted in a significant change in prescribing practice. Our findings suggest that OBLT was both tolerable and had similar outcomes to OPAT.

Paradoxical and bimodal immune-mediated dermatological side effects of TNF-α inhibitors: A comprehensive review.

INTRODUCTION: Due to the increasing prevalence of immune-mediated diseases such as psoriasis, lichen planus, rheumatoid arthritis and inflammatory bowel disease, dermatologists have turned to new biologic drugs known as DMARDs (disease-modifying anti-rheumatic drugs) in recent years. AREAS COVERED: In this study, we evaluate the immune-mediated dermatological side effects of DMARDS by reviewing and analyzing previous peer-reviewed research on the effects of TNF-α inhibitors in the treatment of skin diseases, as well as adverse effects of these drugs and some of the main causes of these effects. EXPERT OPINION: DMARDs are very effective in improving control of the above diseases. TNF-α inhibitors are an important group of DMARDs that are widely used. The paradoxical adverse events (PAEs) associated with the use of TNF-α inhibitors are divided into three categories: true paradoxical, borderline paradoxical, and non-paradoxical. True PAEs include conditions for which TNF-α inhibitors are approved for treatment. Borderline PAEs are considered to occur with this class of drugs for which there is no definite approval but for which there is sufficient evidence. Although these events are rare, early recognition of the accused drug and appropriate decision-making may prevent progression of complications and irreversible side effects.

Use of lipoglycopeptides for moderate to severe ABSSSI in the emergency department.

The burden of acute bacterial skin and skin structure infections (ABSSSI) continue to plague the healthcare system. One approach to managing moderate-to-severe ABSSSI in low-risk patients involves use of a single dose lipoglycopeptide (LGP), dalbavancin or oritavancin, in the emergency department (ED) and discharge to home with follow-up care. Limited ED studies indicate decreased hospital stays, ED revisits, readmissions, and healthcare costs, as well as improved patient satisfaction with use of these antibiotics. However, existing literature has limitations and gaps, such as insufficient quantifiable data on patient selection criteria, outcome predictors, and risk factors leading to treatment failure. Moreover, there is lack of research on the impact of LGPs on organizational productivity, patient quality of life, and utility in indications beyond ABSSSI. This review focuses on the role of long-acting LGPs in the ED setting for select patients presenting with ABSSSI, aiming to avoid hospitalizations, expedite patient discharge, and prevent readmissions while acknowledging potential limitations of therapy. Additionally, it provides insights into strategies and considerations specifically relevant to implementing this therapeutic approach in the ED.

Tattoo-induced allergic contact dermatitis presents diagnostic challenge as a cellulitis mimic.

Allergic contact dermatitis (ACD) is a prevalent condition associated with numerous potential allergen exposures. Tattoo ink is variable and may contain allergens that can be overlooked in patient education and diagnosis. We present a 27-year-old female with ACD following a new tattoo. The patient was repeatedly misdiagnosed with cellulitis by three different clinicians and treated with multiple antibiotics without improvement. The correct diagnosis was eventually made in the emergency department (ED). Although the patient was aware of her allergies to nickel and cobalt from patch testing, she was not aware of the potential for tattoo ink to contain these allergens because prior tattoos had not provoked an allergic reaction. Consequently, the appropriate care was delayed by a month, resulting in significant morbidity. This case demonstrates the potential for ACD to present similarly to cellulitis in an ED setting and the need for clinical vigilance in diagnosis of ACD. It also highlights the importance of detailed patient education on potential allergen sources particularly in the context of tattooing, which is performed with unregulated and variable ink products.

Extensive Invasive Sinusitis Secondary to Streptococcus Intermedius Infection.

Invasive sinusitis is a rare complication of sinusitis. We present the case of a woman, age 72 years, who presented with acute encephalopathy in the setting of sepsis found to have extensive invasive sinusitis with intracranial extension secondary to Streptococcus intermedius, managed with intravenous antibiotics alone. S. intermedius is a rare cause of acute bacterial sinusitis, associated with infections of relatively greater severity and risk of intracranial spread, often requiring a combination of intravenous antibiotics and surgical debridement for source control. Successful treatment of invasive sinusitis with medical management alone may be achievable if surgical intervention is contraindicated. However, the probability of meaningful recovery without surgical source control is rare and is associated with greater morbidity and mortality. Therefore, factors contributing to the success of medical management alone should be investigated.

Comprehensive Statistical Approach to Investigate the Risk Factors Affecting the Occurrences of Cellulitis Episodes among Patients with Lymphedema.

Background: Cellulitis is an infection of the skin and the tissues just under the skin. As any disease, cellulitis has various physiological and physical effects that deteriorate a patient's quality of life. Luckily, cellulitis can be treated when dealt with in a timely fashion. Nonetheless, some patients may experience more than one episode of cellulitis or a recurrence of cellulitis that was previously cured. In fact, the occurrences of cellulitis episodes are believed to follow a statistical distribution. The frequency distribution of cellulitis episodes is scrutinized herein. We aimed to investigate the risk factors that affect the number of cellulitis episodes and the pattern of association between cancer types and cellulitis episodes by using analytical and visual approaches.Methods: A statistical approach applying a two-part count regression model was used instead of the traditional one-part count model. Moreover, multiple correspondence analysis was used to support the finding of count regression models.Results: The results of analysis of the sample from the National Cheng Kung University hospital in Taiwan revealed the mean age of patients was 58.7 ± 14.31 years old. The two-part regression model is conceptually and numerically better than the one-part regression model when examining the risks factors that affect cellulitis episodes. Particularly, we found the significant factors based on the best model are cellulitis history ([Formula: see text]; P value < 0.001), clinical stage of cancer (3) ([Formula: see text]; P value < 0.001), no cancer ([Formula: see text]; P value < 0.05), cancer of female reproductive organs ([Formula: see text]; P value < 0.05), breast cancer ([Formula: see text]; P value < 0.05), and age ≥ 60 years ([Formula: see text]; P value < 0.05). Multiple correspondence analysis approach found cancer types (breast and female reproductive organ), age ≥ 60 years, and cellulitis history were more likely to link to excess zero cellulitis or one cellulitis episode.

Incomplete Kawasaki disease presenting with a cellulitis-like plaque: Lessons from an unusual presentation.

Kawasaki disease (KD) is an acute small to medium-vessel vasculitis that primarily affects children under the age of 5 years. The cause of KD is unknown, but it is hypothesized to be a systemic inflammatory illness triggered by infections in genetically predisposed individuals. Diagnosis of incomplete KD is made in patients with prolonged fever without a source who do not meet diagnostic criteria but have some findings consistent with KD such as elevated inflammatory markers, transaminitis, and echocardiographic findings. We present a 7-year-old boy who developed 10 days of fevers and rash that began 3 days after his first dose of hepatitis A vaccination and had notable features of a peculiar cellulitis-like plaque and peripheral eosinophilia.

Wells syndrome following vaccination: A pediatric case with positive patch test to gelatin.

We report a 12-month-old boy with a skin eruption that developed 15 days after receiving the measles, mumps, rubella (MMR), pneumococcal, and meningococcal vaccines, consistent with the diagnosis of Wells syndrome. Patch testing showed a positive reaction to gelatin, which is used as a stabilizer for both live and inactivated vaccines. Gelatin was only present in the MMR vaccine.

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.

Lower extremity infections: Essential anatomy and multimodality imaging findings.

In modern practice, imaging plays an integral role in the diagnosis, evaluation of extent, and treatment planning for lower extremity infections. This review will illustrate the relevant compartment anatomy of the lower extremities and highlight the role of plain radiographs, CT, US, MRI, and nuclear medicine in the diagnostic workup. The imaging features of cellulitis, abscess and phlegmon, necrotizing soft tissue infection, pyomyositis, infectious tenosynovitis, septic arthritis, and osteomyelitis are reviewed. Differentiating features from noninfectious causes of swelling and edema are discussed.

Imaging features of soft-tissue infections.

Skin and soft tissues are among the most common sites of infections. Infections can involve the superficial epidermis to deep muscles and bones. Most infections spread through contiguous structures, although hematogenous spread can occur in the setting of an immunocompromised state and with atypical infections. While clinical diagnosis of infections is possible, it often lacks specificity, necessitating the use of imaging for confirmation. Cross-sectional imaging with US, CT, and MRI is frequently performed not just for diagnosis, but to delineate the extent of infection and to aid in management. Nonetheless, the imaging features have considerable overlap, and as such, it is essential to integrate imaging features with clinical features for managing soft tissue infections. Radiologists must be aware of the imaging features of different infections and their mimics, as well as the pros and cons of each imaging technique to properly use them for appropriate clinical situations. In this review, we summarize the most recent evidence-based features of key soft tissue infections.