A comparative phenotypic and genomic analysis of methicillin-resistant Staphylococcus aureus ST45 isolates from cellulitis and from 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-MRSAs; n = 6) or osteomyelitis (OM-MRSAs; 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 six 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.

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.

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.

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.

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.

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.

Non-O1 and non-O139 Vibrio cholerae Septicemia and Cellulitis: a Case Report.

Non-O1 and non-O139 Vibrio cholerae (NOVC) are serogroups that do not produce cholera toxin and are not responsible for epidemics. Even though rarely encountered in clinical practice, they can cause a spectrum of different conditions ranging from mild gastrointestinal syndrome to extraintestinal diseases, of which bacteremia and wound infections are the most severe. Risk factors for severe disease are cirrhosis, neoplasms, and diabetes mellitus. The mortality rate of NOVC bacteremia in hospitalized patients ranges from 24 to 61.5%. Incidence of NOVC infections is still rare, and consensus recommendations on treatment are not available. We report a case of NOVC bacteremia associated with severe cellulitis in an immunocompetent 75-year-old man who had eaten raw seafood in a location by the northern Adriatic Sea (Italy). Twenty-four hours after intake, he developed a high fever and vomiting. Afterwards, he started noticing the appearance of cellulitis in his right leg, which worsened in a matter of hours. The patient had a history of compensated type 2 diabetes mellitus. NOVC was isolated from both blood cultures and the leg ulcer. The non-O1, non-O139 serogroup was confirmed, and the detection of the cholera toxin gene was negative. Both tests were performed by the Reference National Laboratory of Istituto Superiore di Sanità (ISS). Multiple antimicrobial regimens were administered, with complete recovery. In conclusion, considering the severity of NOVC-associated manifestations, it is of pivotal importance to reach etiological diagnosis for a target antimicrobial therapy and to consider V. cholerae infection in the differential diagnosis in the presence of risk factors and potential exposure.

Pediatric preseptal and orbital cellulitis - a 6 year experience from a London tertiary centre.

PURPOSE: This study reports the experience of pediatric preseptal and orbital cellulitis at a London tertiary centre during a 6-year period and highlights the role of orbital surgeons in the management of subperiosteal abscess (SPA). METHODS: A retrospective review was conducted of all pediatric patients hospitalised for preseptal and orbital cellulitis. RESULTS: A total of 201 children including 152 cases of preseptal cellulitis and 49 cases of orbital cellulitis were admitted at a London tertiary centre over the study period. Patients with orbital cellulitis and especially those managed surgically had higher rates of fever, higher presenting white cell count and C-reactive protein level compared to cases of preseptal cellulitis. 77.6% of patients with orbital cellulitis had SPA. 81.6% of SPA had a medial component, while 28.9% had superior component. 61.2% of orbital cellulitis cases were managed surgically. Surgical intervention was carried out by otorhinolaryngologists (ENT) in 76.7% of cases, jointly between ENT and orbital surgeons in 16.7% of cases and by orbital surgeons alone in 6.7% of cases. Of the 11 SPA involving the orbital roof, all were surgically managed and orbital surgeons were involved in 54.5% of cases. When SPA involved the medial wall, orbital surgeons were only involved in 6.5% of cases. CONCLUSIONS: We recommend all patients with superior SPA be treated at a centre with both ENT and orbital surgeons as these may not be amenable to drainage by ENT alone.

Sarcoid-like reaction of the orbit in diffuse large B-cell lymphoma.

Sarcoid-like reaction (SLR) has been reported in patients with solid tumor malignancies, lymphomas, and patients receiving immunotherapy. SLR is often incidentally found during positron emission tomography/computed tomography scans as hilar and/or mediastinal lymphadenopathy. SLR has also been found in the lung, spleen, bone marrow, and skin. Biopsy of these lesions shows noncaseating granulomas. When systemic criteria are not met for sarcoidosis, these noncaseating granulomas are termed SLR. We present the first case in the literature of a case of orbital SLR in a patient with concomitant diffuse large B-cell lymphoma and inverted papilloma of the maxillary sinus. This case highlights the importance of including malignancy in the differential for the presence of a noncaseating granuloma in the orbit.

Gonococcal dacryoadenitis complicated by orbital cellulitis: a case report.

Gonococcal dacryoadenitis is uncommon, and its diagnosis may be delayed especially if there is a low index of clinical suspicion. Making an early diagnosis is extremely important because in some cases the organism may spread contiguously, leading to vision-threatening sequelae such as corneal perforation. The authors present a case report of a patient diagnosed with gonococcal dacryoadenitis complicated by orbital cellulitis. Our case demonstrates that in all cases of purulent dacryoadenitis, urgent evaluation, cultures and treatment is crucial, and it is prudent to consider gonococcal dacryoadenitis as a rare but possible differential in patients who are sexually active with an unexplained cause for dacryoadenitis.

Orbital subperiosteal abscess in adolescents and adults: predictors and outcomes of nonsurgical management and surgical approaches.

PURPOSE: The aim of this study was to assess predictors and outcomes of subperiosteal abscess (SPA) management in adolescents and adults at two tertiary care centers. METHODS: This retrospective cohort study included cases of SPA from January 1 2000 to October 9 2022 at two institutions. Patients 9 years or older were categorized into surgical and nonsurgical cohorts. Surgical subgroups included those who underwent functional endoscopic sinus surgery (FESS) alone, external (transcutaneous or transconjunctival) orbitotomy alone, or combined FESS and external surgery. The presented features were assessed as potential treatment predictors. Outcomes included length of stay (LOS), final best-corrected visual acuity (BCVA), readmission rate, and reoperation rate. RESULTS: Of the 159 SPA cases included, 127 (79.9%) underwent surgery and 32 (20.1%) were managed nonsurgically. The nonsurgical cohort was younger (p = .003) with smaller abscesses (p < .001) that were more likely to be medial (p < .001). The nonsurgical cohort had shorter LOS (p < .001); final BCVA and readmission rates were similarly favorable. Abscess location was correlated with surgical approach. Superior SPA that underwent FESS or external surgery alone had higher reoperation rates (57.1.0% and 58.3%, respectively) than combined (17.9%). External approach and FESS alone resulted in lower reoperation rates (15.4% and 15.0%, respectively) than combined (27.3%) for medial SPA. Subgroup analysis in the sinusitis cohort yielded similar results. CONCLUSIONS: A trial of nonsurgical management may be safe and effective for select patients aged 9 years and older with sinusitis-derived, medial, and small SPA. When surgery is indicated, approach should be guided by abscess location to minimize reoperation risk.

Orbital abscess with white eye in patients treated with oral antibiotics for orbital cellulitis.

PURPOSE: To report a case series of seven patients with late presentation of orbital/subperiosteal abscess following oral treatment of orbital cellulitis. METHODS: A retrospective case series of all patients presented with orbital abscess following oral treatment of orbital cellulitis from two tertiary-care eye centres in Riyadh, Saudi Arabia, was conducted. Demographic profiles, risk factors, initial clinical presentation, management regimens, and final outcome were analysed. RESULTS: Patients presented mainly with proptosis and limitation of extraocular motility without external ophthalmic inflammatory signs. Most patients needed surgical evacuation despite the appropriate initiation of intravenous antibiotics following presentation to our hospitals. CONCLUSION: Treating orbital cellulitis with oral antibiotics may lead to delayed presentation of orbital abscess without external ophthalmic inflammatory signs.

Valsalva-associated orbital compartment syndrome in the setting of frontoethmoidal mucocele and orbital cellulitis.

Valsalva-associated orbital compartment syndrome in the setting of orbital cellulitis, mucocele, or subperiosteal abscess has not been previously reported. A previously healthy girl presented with orbital cellulitis complicated by a subperiosteal abscess and frontoethmoidal mucocele. On the day of her planned orbitotomy and endoscopic sinus surgery, she developed a Valsalva-associated retrobulbar hemorrhage and elevated intraocular pressure after crying during a blood glucose fingerstick. An urgent canthotomy and cantholysis in addition to the planned endoscopic sinus procedure was performed. She did well post-operatively with normal vision at follow-up. Based on these experiences, there should be a consideration to implement heightened vigilance to prevent or minimize Valsalva maneuvers in orbital cellulitis patients with subperiosteal abscesses or mucoceles extending into the orbit. While it remains unclear whether and to what degree these patients may be at an increased risk of developing retrobulbar hemorrhage leading to orbital compartment syndrome, we hope that this novel report aids in providing another consideration with the goal of preventing vision loss.