Randomized controlled trial of cephalexin versus clindamycin for uncomplicated pediatric skin infections

Pre- and Post-admission Care for Children Hospitalized With Skin and Soft Tissue Infections

BACKGROUND AND OBJECTIVES

Although skin and soft tissue infections (SSTIs) are among the most common indications for pediatric hospitalization, little is known about outpatient care received for SSTI before and after hospitalization. We assessed peri-hospitalization care for SSTI, including antibiotic exposures and their impact on hospital length of stay (LOS).

METHODS

This is a retrospective cohort study of 1229 SSTI hospitalizations in 2019 from children aged 1-to-18 years enrolled in Medicaid from 10 US states included in the Merative Marketscan Medicaid database. We characterized health service utilization (outpatient visits, laboratory and diagnostic tests, antibiotic exposures) 14 days before and 30 days after hospitalization and evaluated the effects of pre-hospitalization care on hospital LOS with linear regression.

RESULTS

Only 43.1% of children hospitalized with SSTI had a preceding outpatient visit with a SSTI diagnosis, 69.8% of which also filled prescription for an antibiotic. Median LOS for SSTI admission was 2 days (interquartile range 1-3). Pre-hospitalization visits with a diagnosis of SSTI were associated with a 0.7 day reduction (95% confidence interval: 0.6-0.81) in LOS (P < .001), but pre-hospital antibiotic exposure alone had no effect on LOS. Most children (81.7%) filled antibiotic prescriptions after hospital discharge and 74.5% had post-discharge ambulatory visits.

CONCLUSIONS

Although most children did not receive pre-admission care for SSTI, those that did had a shorter hospitalization. Further investigation is necessary on how to optimize access and use of outpatient care for SSTI.

Secondary Bacterial Infections in Patients with Atopic Dermatitis or Other Common Dermatoses

Secondary bacterial infections of common dermatoses such as atopic dermatitis, ectoparasitosis, and varicella zoster virus infections are frequent, with Staphylococcus aureus and Streptococcus pyogenes being the bacteria most involved. There are also Gram-negative infections secondary to common dermatoses such as foot dyshidrotic eczema and tinea pedis. Factors favoring secondary bacterial infections in atopic dermatitis, ectoparasitosis, and varicella zoster virus infections mainly include an epidermal barrier alteration as well as itch. Mite-bacteria interaction is also involved in scabies and some environmental factors can promote Gram-negative bacterial infections of the feet. Furthermore, the bacterial ecology of these superinfections may depend on the geographical origin of the patients, especially in ectoparasitosis. Bacterial superinfections can also have different clinical aspects depending on the underlying dermatoses. Subsequently, the choice of class, course, and duration of antibiotic treatment depends on the severity of the infection and the suspected bacteria, primarily targeting S. aureus. Prevention of these secondary bacterial infections depends first and foremost on the management of the underlying skin disorder. At the same time, educating the patient on maintaining good skin hygiene and reporting changes in the primary lesions is crucial. In the case of recurrent secondary infections, decolonization of S. aureus is deemed necessary, particularly in atopic dermatitis.

Therapeutic Options and Outcomes for the Treatment of Children with Gram-Positive Bacteria with Resistances of Concern: A Systematic Review

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant coagulase-negative Staphylococci (MR-CoNS), and vancomycin-resistant Enterococci (VRE) are increasing worldwide and represent a threat for the limited treatment options in pediatric patients and neonates compared to adults. Recommendations in pediatrics are mainly extrapolated from adults' studies.

METHODS

A literature search for the treatment of these pathogens in children (<18 years old) was conducted in Embase, MEDLINE, and Cochrane Library. Studies reporting data on single-patient-level outcomes related to a specific antibiotic treatment for multidrug resistant (MDR) Gram-positive bacterial infection in children were included. Studies reporting data from adults and children were included if single-pediatric-level information could be identified (PROSPERO registration: CRD42022383867).

RESULTS

The search identified 11,740 studies (since January 2000), of which 48 fulfilled both the inclusion and the exclusion criteria and were included in the analysis: 29 for MRSA, 20 for VRE, and seven for MR-CoNS. Most studies were retrospective studies. Vancomycin was mainly used as a comparator, while linezolid and daptomycin were the most studied antimicrobials showing good efficacy.

CONCLUSIONS

Linezolid showed a safety and efficacy profile in a neonatal setting; daptomycin is increasingly used for MRSA, but the evidence is scarce for VRE.

Economic Viability of Penicillin Allergy Testing to Avoid Improper Clindamycin Surgical Prophylaxis

OBJECTIVE

Patients mislabeled with a penicillin allergy are often unnecessarily given prophylactic clindamycin. Thus, otolaryngologists may cause harm due to clindamycin's associated risk of Clostridioides difficile infections (CDI) and surgical site infections (SSI). The objective of this study was to determine the economic feasibility of penicillin allergy testing in preventing unnecessary clindamycin use among patients with an unconfirmed penicillin allergy prior to otolaryngologic surgery.

METHODS

A break-even analysis was performed using the average cost of penicillin allergy testing and a CDI/SSI to calculate the absolute risk reduction (ARR) in baseline CDI/SSI rate due to clindamycin required for penicillin testing to be economically sustainable. The binomial distribution was used to calculate the probability that current penicillin testing can achieve this study's ARR.

RESULTS

Preoperative penicillin testing was found to be economically sustainable if it could decrease the baseline CDI rate by an ARR of 1.06% or decrease the baseline SSI rate by an ARR of 1.34%. The probability of penicillin testing achieving these ARRs depended on the baseline CDI and SSI rates. When the CDI rate was at least 5% or the SSI rate was at least 7%, penicillin allergy testing was guaranteed to achieve economic sustainability.

CONCLUSION

In patients mislabeled with a penicillin allergy, preoperative penicillin allergy testing may be an economically sustainable option to prevent the unnecessary use of prophylactic clindamycin during otolaryngologic surgery. Current practice guidelines should be modified to recommend penicillin allergy testing in patients with an unconfirmed allergy prior to surgery.

LEVEL OF EVIDENCE

N/A Laryngoscope, 2022.

Broad Utility of a Minimally Invasive Technique for Pediatric Wound Care: Simple and Effective

OBJECTIVE

Infected or contaminated wound sites have historically been managed with incision and drainage. Here, the authors review their experience with skin closure over vessel loops and assess the results of this technique in a variety of clinical situations, hypothesizing that minimally invasive drainage strategies are associated with a decrease in common postoperative complications.

METHODS

Investigators retrospectively reviewed the data of all children with infected or contaminated wound sites operated on by a single surgeon with skin closure over vessel loops from September 2016 to September 2018. Demographics, indications for surgery, complications, and follow-up were assessed.

RESULTS

Over a 2-year period, 33 children underwent skin closure over vessel loops. The majority were female (82%), Hispanic/Latino (40%), and younger than 5 years (58%; range, 4 months to 16 years). One-third were obese. Reasons for intervention included skin and soft tissue infection (64%), trauma (15%), and ostomy closure (6%). Median postoperative length of stay was 1 day. Three-quarters (76%) of the patients returned to the clinic for follow-up and/or vessel loop removal. At 30 days after operation, no patients in this cohort returned to the ED with recurrent infection or wound dehiscence.

CONCLUSIONS

This minimally invasive technique for contaminated wound management demonstrates no evidence of subsequent infection in standard follow-up. These results are indicative of specific advantages related to vessel loop drainage, including shorter lengths of stay and ease of wound maintenance, in a variety of challenging clinical scenarios.

Specific staphylococcal cassette chromosome mec (SCCmec) types and clonal complexes are associated with low-level amoxicillin/clavulanic acid and cefalotin resistance in methicillin-resistant Staphylococcus pseudintermedius

Background

Staphylococcus pseudintermedius is a common pathogen in dogs and methicillin resistance has emerged over recent decades. According to the current guidelines, S. pseudintermedius displaying oxacillin resistance should be reported as resistant to all β-lactams.

Objectives

To identify possible associations between β-lactam resistance levels and clonal complexes (CCs) and/or staphylococcal cassette chromosome mec (SCCmec) types in methicillin-resistant S. pseudintermedius (MRSP).

Methods

MICs of oxacillin, penicillin, ampicillin, amoxicillin/clavulanic acid and cefalotin were determined by broth microdilution for 86 clinical canine MRSP isolates from Denmark and the Netherlands. PCR and sequencing were used for SCCmec typing and MLST.

Results

Isolates belonged to CC71 (n = 36), CC258 (n = 33), CC45 (n = 11), CC68 (n = 1) and five singleton STs. SCCmecII-III was exclusively found in CC71 and SCCmecIV was significantly associated with CC258. SCCmecV and non-typeable SCCmec types occurred in 4 and 14 isolates, respectively. SCCmecIV was associated with lower MICs of oxacillin (<2 mg/L), ampicillin (<8 mg/L) and amoxicillin/clavulanic acid (<4 mg/L) and with susceptibility to cefalotin (<4 mg/L). All isolates harbouring SCCmecV were susceptible to cefalotin as well.

Conclusions

SCCmec types were associated with different CCs and with either high- or low-level resistance to different β-lactams. The finding of amoxicillin/clavulanic acid (20%) and cefalotin (70%) in vitro susceptibility across all CCs might have clinical implications, since amoxicillin/clavulanic acid and first-generation cephalosporins are first-choice antibiotics for treatment of S. pseudintermedius infections. Pharmacokinetic/pharmacodynamic and clinical outcome studies are warranted to evaluate the in vivo efficacy of these β-lactams for treatment of MRSP infections.

Interventions for bacterial folliculitis and boils (furuncles and carbuncles)

BACKGROUND

Bacterial folliculitis and boils are globally prevalent bacterial infections involving inflammation of the hair follicle and the perifollicular tissue. Some folliculitis may resolve spontaneously, but others may progress to boils without treatment. Boils, also known as furuncles, involve adjacent tissue and may progress to cellulitis or lymphadenitis. A systematic review of the best evidence on the available treatments was needed.

OBJECTIVES

To assess the effects of interventions (such as topical antibiotics, topical antiseptic agents, systemic antibiotics, phototherapy, and incision and drainage) for people with bacterial folliculitis and boils.

SEARCH METHODS

We searched the following databases up to June 2020: the Cochrane Skin Specialised Register, CENTRAL, MEDLINE, and Embase. We also searched five trials registers up to June 2020. We checked the reference lists of included studies and relevant reviews for further relevant trials.  SELECTION CRITERIA: We included randomised controlled trials (RCTs) that assessed systemic antibiotics; topical antibiotics; topical antiseptics, such as topical benzoyl peroxide; phototherapy; and surgical interventions in participants with bacterial folliculitis or boils. Eligible comparators were active intervention, placebo, or no treatment.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Our primary outcomes were 'clinical cure' and 'severe adverse events leading to withdrawal of treatment'; secondary outcomes were 'quality of life', 'recurrence of folliculitis or boil following completion of treatment', and 'minor adverse events not leading to withdrawal of treatment'. We used GRADE to assess the certainty of the evidence.

MAIN RESULTS

We included 18 RCTs (1300 participants). The studies included more males (332) than females (221), although not all studies reported these data. Seventeen trials were conducted in hospitals, and one was conducted in clinics. The participants included both children and adults (0 to 99 years). The studies did not describe severity in detail; of the 232 participants with folliculitis, 36% were chronic. At least 61% of participants had furuncles or boils, of which at least 47% were incised. Duration of oral and topical treatments ranged from 3 days to 6 weeks, with duration of follow-up ranging from 3 days to 6 months. The study sites included Asia, Europe, and America. Only three trials reported funding, with two funded by industry. Ten studies were at high risk of 'performance bias', five at high risk of 'reporting bias', and three at high risk of 'detection bias'. We did not identify any RCTs comparing topical antibiotics against topical antiseptics, topical antibiotics against systemic antibiotics, or phototherapy against sham light. Eleven trials compared different oral antibiotics. We are uncertain as to whether cefadroxil compared to flucloxacillin (17/21 versus 18/20, risk ratio (RR) 0.90, 95% confidence interval (CI) 0.70 to 1.16; 41 participants; 1 study; 10 days of treatment) or azithromycin compared to cefaclor (8/15 versus 10/16, RR 1.01, 95% CI 0.72 to 1.40; 31 participants; 2 studies; 7 days of treatment) differed in clinical cure (both very low-certainty evidence). There may be little to no difference in clinical cure rate between cefdinir and cefalexin after 17 to 24 days (25/32 versus 32/42, RR 1.00, 95% CI 0.73 to 1.38; 74 participants; 1 study; low-certainty evidence), and there probably is little to no difference in clinical cure rate between cefditoren pivoxil and cefaclor after 7 days (24/46 versus 21/47, RR 1.17, 95% CI 0.77 to 1.78; 93 participants; 1 study; moderate-certainty evidence). For risk of severe adverse events leading to treatment withdrawal, there may be little to no difference between cefdinir versus cefalexin after 17 to 24 days (1/191 versus 1/200, RR 1.05, 95% CI 0.07 to 16.62; 391 participants; 1 study; low-certainty evidence). There may be an increased risk with cefadroxil compared with flucloxacillin after 10 days (6/327 versus 2/324, RR 2.97, 95% CI 0.60 to 14.62; 651 participants; 1 study; low-certainty evidence) and cefditoren pivoxil compared with cefaclor after 7 days (2/77 versus 0/73, RR 4.74, 95% CI 0.23 to 97.17; 150 participants; 1 study; low-certainty evidence). However, for these three comparisons the 95% CI is very wide and includes the possibility of both increased and reduced risk of events. We are uncertain whether azithromycin affects the risk of severe adverse events leading to withdrawal of treatment compared to cefaclor (274 participants; 2 studies; very low-certainty evidence) as no events occurred in either group after seven days. For risk of minor adverse events, there is probably little to no difference between the following comparisons: cefadroxil versus flucloxacillin after 10 days (91/327 versus 116/324, RR 0.78, 95% CI 0.62 to 0.98; 651 participants; 1 study; moderate-certainty evidence) or cefditoren pivoxil versus cefaclor after 7 days (8/77 versus 5/73, RR 1.52, 95% CI 0.52 to 4.42; 150 participants; 1 study; moderate-certainty evidence). We are uncertain of the effect of azithromycin versus cefaclor after seven days due to very low-certainty evidence (7/148 versus 4/126, RR 1.26, 95% CI 0.38 to 4.17; 274 participants; 2 studies). The study comparing cefdinir versus cefalexin did not report data for total minor adverse events, but both groups experienced diarrhoea, nausea, and vaginal mycosis during 17 to 24 days of treatment. Additional adverse events reported in the other included studies were vomiting, rashes, and gastrointestinal symptoms such as stomach ache, with some events leading to study withdrawal. Three included studies assessed recurrence following completion of treatment, none of which evaluated our key comparisons, and no studies assessed quality of life.

AUTHORS' CONCLUSIONS

We found no RCTs regarding the efficacy and safety of topical antibiotics versus antiseptics, topical versus systemic antibiotics, or phototherapy versus sham light for treating bacterial folliculitis or boils. Comparative trials have not identified important differences in efficacy or safety outcomes between different oral antibiotics for treating bacterial folliculitis or boils. Most of the included studies assessed participants with skin and soft tissue infection which included many disease types, whilst others focused specifically on folliculitis or boils. Antibiotic sensitivity data for causative organisms were often not reported. Future trials should incorporate culture and sensitivity information and consider comparing topical antibiotic with antiseptic, and topical versus systemic antibiotics or phototherapy.

Treatment of methicillin-resistant Staphylococcus aureus (MRSA): updated guidelines from the UK

These evidence-based guidelines are an updated version of those issued in 2008. They have been produced following a review of the published literature (2007-18) pertaining to the treatment of infections caused by MRSA. The guidelines update, where appropriate, previous recommendations, taking into account changes in the UK epidemiology of MRSA, ongoing national surveillance data and the efficacy of novel anti-staphylococcal agents licensed for use in the UK. Emerging therapies that have not been licensed for use in the UK at the time of the review have also been assessed.

Calculated initial parenteral treatment of bacterial infections: Skin and soft tissue infections

This is the ninth chapter of the guideline "Calculated Parenteral Initial Therapy of Adult Bacterial Disorders - Update 2018" in the 2nd updated version. The German guideline by the Paul-Ehrlich-Gesellschaft für Chemotherapie e.V. (PEG) has been translated to address an international audience. The chapter contains the first German S2k guidelines for bacterial skin and soft tissue infections. They encompass recommendations on diagnosis and treatment of the defined entities erysipelas (caused by beta-hämolytic streptococci), limited superficial cellulitis (S. aureus), severe cellulitis, abscess, complicated skin and soft tissue infections, infections of feet in diabetic patients ("diabetic foot"), necrotizing soft tissue infection and bite injuries.

S2k guidelines for skin and soft tissue infections Excerpts from the S2k guidelines for "calculated initial parenteral treatment of bacterial infections in adults - update 2018"

These first German S2k guidelines for bacterial skin and soft tissue infections were developed as one chapter of the recommendations for "calculated initial parenteral treatment of bacterial infections" issued under the auspices of the Paul-Ehrlich Society, of which the main part is presented here. Well-calculated antibiotic therapies require precise diagnostic criteria. Erysipelas is defined as non-purulent infection considered to be caused by beta-hemolytic strepto-cocci. It is diagnosed clinically by its bright-red erythema and early fever or chills at disease onset. Penicillin is the treatment of choice. Limited soft tissue infection (cellulitis) is usually caused by Staphylococcus (S.) aureus, frequently originates from chronic wounds and presents with a more violaceous-red hue and only rarely with initial fever or chills. Treatment consists of first- or second--generation cephalosporins or flucloxacillin (IV). Severe cellulitis is a purulent, partially necrotic infection which extends through tissue boundaries to fascias and requires surgical management in addition to antibiotics. Moreover, it frequently fulfills the criteria for "complicated soft tissue infections", as previously defined by the Food and Drug Administration for use in clinical trials (they include comorbidities such as uncontrolled diabetes, peripheral artery disease, neutropenia). It requires antibiotics which besides S. aureus target anaerobic and/or gramnegative bacteria. The rare so-called necrotizing skin and soft tissue infections represent a distinct entity. They are characterized by rapid, life-threatening progression due to special bacterial toxins that cause ischemic necrosis and shock and need rapid and thorough debridement in addition to appropriate antibiotics. For cutaneous abscesses the first-line treatment is adequate drainage. Additional antibiotic therapy is required only under certain circumstances (e.g., involvement of the face, hands, or anogenital region, or if drainage is somehow complicated). The present guidelines also contain consensus-based recommendations for higher doses of antibiotics than those approved or usually given in clinical trials. The goal is to deliver rational antibiotic treatment that is both effective and well-tolerated and that exerts no unnecessary selection pressure in terms of multidrug resistance.

Ability of Bicarbonate Supplementation To Sensitize Selected Methicillin-Resistant Staphylococcus aureus Strains to β-Lactam Antibiotics in an Ex Vivo Simulated Endocardial Vegetation Model

Supplementation of standard growth media (cation-adjusted Mueller-Hinton Broth [CAMHB]) with bicarbonate (NaHCO3) increases β-lactam susceptibility of selected methicillin-resistant Staphylococcus aureus (MRSA) strains ("NaHCO3 responsive"). This "sensitization" phenomenon translated to enhanced β-lactam efficacy in a rabbit model of endocarditis. The present study evaluated NaHCO3-mediated β-lactam MRSA sensitization using an ex vivo pharmacodynamic model, featuring simulated endocardial vegetations (SEVs), to more closely mimic the host microenvironment. Four previously described MRSA strains were used: two each exhibiting in vitro NaHCO3-responsive or NaHCO3-nonresponsive phenotypes. Cefazolin (CFZ) and oxacillin (OXA) were evaluated in CAMHB with or without NaHCO3 Intra-SEV MRSA killing was determined over 72-h exposures. In both "responsive" strains, supplementation with 25 mM or 44 mM NaHCO3 significantly reduced β-lactam MICs to below the OXA susceptibility breakpoint (≤4 mg/liter) and resulted in bactericidal activity (≥3-log killing) in the model for both OXA and CFZ. In contrast, neither in vitro-defined nonresponsive MRSA strain showed significant sensitization in the SEV model to either β-lactam. At both NaHCO3 concentrations, the fractional time above MIC was >50% for both CFZ and OXA in the responsive MRSA strains. Also, in media containing RPMI plus 10% Luria-Bertani broth (proposed as a more host-mimicking microenvironment and containing 25 mM NaHCO3), both CFZ and OXA exhibited enhanced bactericidal activity against NaHCO3-responsive strains in the SEV model. Neither CFZ nor OXA exposures selected for emergence of high-level β-lactam-resistant mutants within SEVs. Thus, in this ex vivo model of endocarditis, in the presence of NaHCO3 supplementation, both CFZ and OXA are highly active against MRSA strains that demonstrate similar enhanced susceptibility in NaHCO3-supplemented media in vitro.

The safety of treatment options for acute bacterial skin and skin structure infections

INTRODUCTION

Acute bacterial skin and skin-structure infections (ABSSSI) may develop in both in-patients and out-patients, possibly with a severe clinical presentation. Since most phase 3 randomized clinical trials have shown non-inferiority in efficacy across different agents, considerations regarding their different safety profiles inevitably play a crucial role in the everyday choice about which of them should be employed for the treatment of ABSSSI.

AREAS COVERED

In this review, the authors discuss the safety profile of different treatment options for ABSSSI.

EXPERT OPINION

The spread of methicillin-resistant Staphylococcus aureus (MRSA) in the last decades has inevitably influenced the therapeutic approach to ABSSSI. Adequate knowledge of the peculiar toxicity profile of each drug active against MRSA is essential for guiding, monitoring and managing adverse events, in turn reducing any unfavorable impact of toxicity on patients' outcomes. In the next five years, potential toxicity will play a critical role in establishing the best available therapy for each specific patient, together with consideration regarding the possibility of avoiding hospitalization or allowing a switch from intravenous to oral therapy and early discharge.

Common Community-acquired Bacterial Skin and Soft-tissue Infections in Children: an Intersociety Consensus on Impetigo, Abscess, and Cellulitis Treatment

PURPOSE

The main objective of this article was to offer practical suggestions, given the existing evidence, for identifying and managing bacterial impetigo, abscess, and cellulitis in ambulatory and hospital settings.

METHODS

Five Italian pediatric societies appointed a core working group. In selected conditions, specially trained personnel evaluated quality assessment of treatment strategies according to the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. Only randomized controlled trials (RCTs) and observational studies were included for quality assessment according to the GRADE methodology. MEDLINE, Ovid MEDLINE, EMBASE, and Cochrane Library databases were searched with a strategy combining MeSH and free text terms.

FINDINGS

The literature review included 364 articles focusing on impetigo, skin abscess, and cellulitis/orbital cellulitis. The articles included for quality assessment according to the GRADE methodology for impetigo comprised 5 RCTs and 1 observational study; for skin abscess, 10 RCTs and 3 observational studies were included; for cellulitis and erysipelas, 5 RCTs and 5 observational studies were included; and for orbital cellulitis, 8 observational studies were included. Recommendations were formulated according to 4 grades of strength for each specific topic (impetigo, skin abscesses, cellulitis, and orbital cellulitis). Where controversies arose and expert opinion was considered fundamental due to lack of evidence, agreement according to Delphi consensus recommendations was included.

IMPLICATIONS

Based on a literature review and on local epidemiology, this article offers practical suggestions for use in both ambulatory and hospital settings for managing the most common bacterial SSTIs.

Antibiotic Susceptibility and Treatment Response in Bacterial Skin Infection

Background

Bacterial skin infections occur secondarily in conditions involving a vulnerable skin barrier such as atopic eczema, as well as primarily such as impetigo. They are mainly caused by Staphylococcus aureus and Streptococci. Recently, the prevalence of methicillin-resistant S. aureus has been increasing.

Objective

To determine the characteristics of community-acquired bacterial skin infections, to observe their antibiotic susceptibility patterns, and to evaluate factors contributing to the treatment response.

Methods

We retrospectively reviewed outpatients under 30 years old from 2010 to 2015, from whom we had taken skin swabs for antibiotic susceptibility testing. We collected clinical and microbiological characteristics from the medical records.

Results

We evaluated the culture results of 197 patients and reviewed their medical records. Overall, 86.3% (n=170) of the patients responded to the initial treatment regimen. S. aureus was the most commonly isolated pathogen (52.6%) and showed a high resistance rate to penicillin (90.9%) and oxacillin (36.3%). In the multivariable logistic regression analysis, resistance to 3 or more antibiotics (p=0.044), culture amounts described as “many” (p=0.040), and non-systemic antibiotic use (p<0.001) were significantly associated with lower treatment response. However, methicillin resistance was not associated with lower treatment response both in univariable and multivariable analyses.

Conclusion

Among young patients, S. aureus was the most predominant pathogen present in bacterial skin infections. Resistance to high numbers of antibiotics and the use of non-systemic antibiotics were associated with lower treatment response. First-generation cephalosporins may be the most effective first-line empirical regimen for bacterial skin infections treated in outpatient settings, regardless of methicillin resistance.

Impact of Systemic Antibiotics on Staphylococcus aureus Colonization and Recurrent Skin Infection

Background

Staphylococcus aureus colonization poses risk for subsequent skin and soft tissue infection (SSTI). We hypothesized that including systemic antibiotics in the management of S. aureus SSTI, in conjunction with incision and drainage, would reduce S. aureus colonization and incidence of recurrent infection.

Methods

We prospectively evaluated 383 children with S. aureus SSTI requiring incision and drainage and S. aureus colonization in the anterior nares, axillae, or inguinal folds at baseline screening. Systemic antibiotic prescribing at the point of care was recorded. Repeat colonization sampling was performed within 3 months (median, 38 days; interquartile range, 22-50 days) in 357 participants. Incidence of recurrent infection was ascertained for up to 1 year.

Results

Participants prescribed guideline-recommended empiric antibiotics for purulent SSTI were less likely to remain colonized at follow-up sampling (adjusted hazard ratio [aHR], 0.49; 95% confidence interval [CI], .30-.79) and less likely to have recurrent SSTI (aHR, 0.57; 95% CI, .34-.94) than those not receiving guideline-recommended empiric antibiotics for their SSTI. Additionally, participants remaining colonized at repeat sampling were more likely to report a recurrent infection over 12 months (aHR, 2.37; 95% CI, 1.69-3.31). Clindamycin was more effective than trimethoprim-sulfamethoxazole (TMP-SMX) in eradicating S. aureus colonization (44% vs 57% remained colonized, P = .03) and preventing recurrent SSTI (31% vs 47% experienced recurrence, P = .008).

Conclusions

Systemic antibiotics, as part of acute SSTI management, impact S. aureus colonization, contributing to a decreased incidence of recurrent SSTI. The mechanism by which clindamycin differentially affects colonization and recurrent SSTI compared to TMP-SMX warrants further study.

Ultrasound-Guided Drainage for Pediatric Soft Tissue Abscesses Decreases Clinical Failure Rates Compared to Drainage Without Ultrasound: A Retrospective Study

OBJECTIVES

Soft tissue abscesses are common in the pediatric emergency department (ED). Ultrasound (US) can be used to both diagnose soft tissue abscesses as well as guide drainage. We hypothesized that clinical failure rates would be less in pediatric patients with suspected skin abscesses when evaluated with US.

METHODS

We performed a retrospective review of suspected pediatric skin abscesses at 4 EDs over a 22-month period. Cases were identified through electronic medical record descriptions, discharge diagnoses, and US database records. Data on US use, findings, and outcomes were abstracted to an electronic database. Comparisons between groups included US versus non-US (primary outcome) as well as surgical drainage vs nonsurgical drainage (secondary outcome).

RESULTS

A total of 377 patients were seen with concern for a potential skin abscess; 141 patients (37.4%) underwent US imaging during their visit, and 239 (63.4%) underwent incision and drainage (I&D) during their ED stay: 90 with US and 149 without. The failure rate for patients evaluated with US was significantly lower than that for those evaluated without US (4.4% versus 15.6%; P < .005). Thirty-four (11.3%) of the 302 patients with a diagnosis of an abscess failed therapy: 19 (8.2%) after I&D and 15 (21.1%) after nonsurgical management. Failure after I&D was associated with a smaller abscess cavity on US imaging (17.2 versus 44.8 mm³ ; P < .05).

CONCLUSIONS

The use of US for patients with a suspected skin abscess was associated with a reduction in the amount of clinical failure rates after both surgical drainage and nonsurgical therapy. Ultrasound should be used when evaluating or treating patients with abscesses.

The rise of methicillin resistant Staphylococcus aureus: now the dominant cause of skin and soft tissue infection in Central Australia

This study aimed to examine the epidemiology and treatment outcomes of community-onset purulent staphylococcal skin and soft tissue infections (SSTI) in Central Australia. We performed a prospective observational study of patients hospitalised with community-onset purulent staphylococcal SSTI (n = 160). Indigenous patients accounted for 78% of cases. Patients were predominantly young adults; however, there were high rates of co-morbid disease. Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) was the dominant phenotype, accounting for 60% of cases. Hospitalisation during the preceding 6 months, and haemodialysis dependence were significant predictors of CA-MRSA infection on univariate analysis. Clinical presentation and treatment outcomes were found to be comparable for methicillin-susceptible S. aureus (MSSA) and methicillin-resistant cases. All MRSA isolates were characterised as non-multi-resistant, with this term used interchangeably with CA-MRSA in this analysis. We did not find an association between receipt of an active antimicrobial agent within the first 48 h, and progression of infection; need for further surgical debridement; unplanned General Practitioner or hospital re-presentation; or need for further antibiotics. At least one adverse outcome was experienced by 39% of patients. Clindamycin resistance was common, while rates of trimethoprim-sulfamethoxazole resistance were low. This study suggested the possibility of healthcare-associated transmission of CA-MRSA. This is the first Australian report of CA-MRSA superseding MSSA as the cause of community onset staphylococcal SSTI.

Diagnostic microbiology in veterinary dermatology: present and future

BACKGROUND

The microbiology laboratory can be perceived as a service provider rather than an integral part of the healthcare team.

OBJECTIVES

The aim of this review is to discuss the current challenges of providing a state-of-the-art diagnostic veterinary microbiology service including the identification (ID) and antimicrobial susceptibility testing (AST) of key pathogens in veterinary dermatology.

METHODS

The Study Group for Veterinary Microbiology (ESGVM) of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) identified scientific, technological, educational and regulatory issues impacting the predictive value of AST and the quality of the service offered by microbiology laboratories.

RESULTS

The advent of mass spectrometry has significantly reduced the time required for ID of key pathogens such as Staphylococcus pseudintermedius. However, the turnaround time for validated AST methods has remained unchanged for many years. Beyond scientific and technological constraints, AST methods are not harmonized and clinical breakpoints for some antimicrobial drugs are either missing or inadequate. Small laboratories, including in-clinic laboratories, are usually not adequately equipped to run up-to-date clinical microbiologic diagnostic tests.

CONCLUSIONS AND CLINICAL IMPORTANCE

ESGVM recommends the use of laboratories employing mass spectrometry for ID and broth micro-dilution for AST, and offering assistance by expert microbiologists on pre- and post-analytical issues. Setting general standards for veterinary clinical microbiology, promoting antimicrobial stewardship, and the development of new, validated and rapid diagnostic methods, especially for AST, are among the missions of ESGVM.

Epidemiology of Oral and Maxillofacial Infections

Dental caries and periodontal disease are the most common dental infections and are constantly increasing worldwide. Distribution, occurrence of dental caries, gingivitis, periodontitis, odontogenic infections, antibiotic resistance, oral mucosal infections, and microbe-related oral cancer are important to understand the public impact and methods of controlling such disease. Distribution of human papilloma virus and human immunodeficiency virus -related oral cancers in the US population is presented.

Prevention of Recurrent Staphylococcal Skin Infections

Staphylococcus aureus infections pose a significant health burden. The emergence of community-associated methicillin-resistant S aureus has resulted in an epidemic of skin and soft tissue infections (SSTI), and many patients experience recurrent SSTI. As S aureus colonization is associated with subsequent infection, decolonization is recommended for patients with recurrent SSTI or in settings of ongoing transmission. S aureus infections often cluster within households, and asymptomatic carriers serve as reservoirs for transmission; therefore, a household approach to decolonization is more effective than measures performed by individuals alone. Novel strategies for the prevention of recurrent SSTI are needed.

Clostridium difficile infection following systemic antibiotic administration in randomised controlled trials: a systematic review and meta-analysis

Antibiotics have been the most important risk factor for Clostridium difficile infection (CDI). However, only data from non-randomised studies have been reviewed. We sought to evaluate the risk for development of CDI associated with the major antibiotic classes by analysing data from randomised controlled trials (RCTs). The PubMed, Cochrane and Scopus databases were searched and the references of selected RCTs were also hand-searched. Eligible studies should have compared only one antibiotic versus another administered systemically. Inclusion of studies comparing combinations of antibiotics was allowed only if the second antibiotic was the same or from the same class or if it was administered in a subset of the enrolled patients who were equally distributed in the two arms. Only a minority of the selected RCTs (79/1332; 5.9%) reported CDI episodes. Carbapenems were associated with more CDI episodes than fluoroquinolones [risk ratio (RR) = 2.44, 95% confidence interval (CI) 1.32-4.49] and cephalosporins (RR = 2.24, 95% CI 1.46-3.42), but not penicillins (RR = 2.53, 95% CI 0.87-7.41). Cephalosporins were associated with more CDIs than penicillins (RR = 2.36, 95% CI 1.32-4.23) and fluoroquinolones (RR = 2.84, 95% CI 1.60-5.06). There was no difference in CDI frequency between fluoroquinolones and penicillins (RR = 1.34, 95% CI 0.55-3.25). Finally, clindamycin was associated with more CDI episodes than cephalosporins and penicillins (RR = 3.92, 95% CI 1.15-13.43). In conclusion, data from RCTs showed that clindamycin and carbapenems were associated with more CDIs than other antibiotics.

Frequent bacterial skin and soft tissue infections: diagnostic signs and treatment

Skin and soft tissue infections rank among the most frequent infections worldwide. Classic erysipelas is defined as a non-purulent infection by beta-hemolytic streptococci. The typical signs are tender, warm, bright erythema with tongue-like extensions and early systemic symptoms such as fever or at least chills. Erysipelas always and best responds to penicillin. Limited soft tissue infection or limited cellulitis are the terms we have introduced for infections frequently caused by S. aureus and often originating from chronic wounds or acute trauma. Clinically, they are marked by tender, erythematous swelling which, unlike erysipelas, exhibit a darker red hue and is not always accompanied by fever or chills at onset. Severe cellulitis is a purulent, partially necrotic infection extending to the fascia, with general symptoms of infection, requiring surgical management in addition to antibiotics. It often fulfils criteria of so-called complicated soft tissue infections according to the definition of the FDA, due to their frequent association with e.g. severe diabetes mellitus, peripheral arterial occlusive disease or severe immunosuppression. In contrast, the rare necrotizing skin and soft tissue infections represent a distinct entity, characterized by rapid progression to ischemic necroses and shock due to special bacterial toxins. Limited cellulitis should be treated with cephalosporins group 1 or 2, or, when S.aureus is the isolated or highly likely causative agent, isoxazolyl-penicillins (exploiting their minimal selection pressure on other bacteria). For severe cellulitis, initial antibiotic treatment (mostly iv) includes - depending on the location - agents also active against gram-negative and/or anaerobic bacteria. (e.g. clindamycine, aminopeniclilline with inhibitors of betalaktamase, fluochinolons, cephalosporines group 4). For cutaneous abscesses, drainage presents the therapy of choice. Only under certain conditions additional antibiotic therapy is required. Adherence to the diagnostic criteria and to evidence-based or consensus-derived treatment recommendations as presented herein should allow for an antibiotic therapy with a good balance of efficacy, tolerability by patients and low selection pressure for highly resistant bacteria.

Clinical management of skin and soft tissue infections in the U.S. Emergency Departments

Introduction

Community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) has emerged as the most common cause of skin and soft-tissue infections (SSTI) in the United States. A nearly three-fold increase in SSTI visit rates had been documented in the nation’s emergency departments (ED). The objective of this study was to determine characteristics associated with ED performance of incision and drainage (I+D) and use of adjuvant antibiotics in the management of skin and soft tissue infections (SSTI).

Methods

Cross-sectional study of the National Hospital Ambulatory Medical Care Survey, a nationally representative database of ED visits from 2007–09. Demographics, rates of I+D, and adjuvant antibiotic therapy were described. We used multivariable regression to identify factors independently associated with use of I+D and adjuvant antibiotics.

Results

An estimated 6.8 million (95% CI: 5.9–7.8) ED visits for SSTI were derived from 1,806 sampled visits; 17% were for children <18 years of age and most visits were in the South (49%). I+D was performed in 27% (95% CI 24–31) of visits, and was less common in subjects <18 years compared to adults 19–49 years (p<0.001), and more common in the South. Antibiotics were prescribed for 85% of SSTI; there was no relationship to performance of I+D (p=0.72). MRSA-active agents were more frequently prescribed after I+D compared to non-drained lesions (70% versus 56%, p<0.001). After multivariable adjustment, I+D was associated with presentation in the South (OR 2.36; 95% CI 1.52–3.65 compared with Northeast), followed by West (OR 2.13; 1.31–3.45), and Midwest (OR 1.96; 1.96–3.22).

Conclusion

Clinical management of most SSTIs in the U.S. involves adjuvant antibiotics, regardless of I+D. Although not necessarily indicated, CA-MRSA effective therapy is being used for drained SSTI.

Scratching the surface: a review of skin and soft tissue infections in children

PURPOSE OF REVIEW

We present data from recently conducted research on the diagnosis and management of skin and soft tissue infections (SSTIs) in children.

RECENT FINDINGS

Current research in the area of SSTIs (cellulitis and abscess) has focused on the use of ultrasound, risk factors associated with bacteremia, antibiotic choice, and incision and drainage (I&D) practices. When clinical examination is equivocal at distinguishing abscess from cellulitis, ultrasound can aid in the diagnosis and alter management. Bacteremia is rare in immunocompetent children with uncomplicated SSTIs; blood cultures may be reserved for complicated cases and for those who are systemically ill. Despite the increased prevalence of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA), I&D without antibiotics remains the first-line therapy for abscess. Antibiotics for uncomplicated cellulitis should target β-hemolytic streptococci and methicillin-susceptible S. aureus (MSSA). There are significant variations in pain and sedation practices for I&D, with substantive evidence for the use of topical anesthetics. Wound packing after I&D may not confer significant benefit.

SUMMARY

Evidence to aid in the diagnosis and management of SSTIs in children has emerged in recent years; however, larger prospective pediatric studies are needed.

Treatment outcome measures for randomized controlled trials of antibiotic treatment for acute bacterial skin and skin structure infections in the emergency department setting

Acute bacterial skin and skin structure infections (ABSSSIs), which include cellulitis, abscesses, and wound infections, are among the most commonly encountered conditions in emergency departments (EDs) internationally. Primarily, as a result of the recent epidemic of community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) in North America, ED attendances and hospital admissions secondary to ABSSSIs have increased significantly. First-line antibiotic drug therapies for ABSSSIs have therefore changed to take account of CA-MRSA and the threat of evolving antibiotic resistance. Prior to 2010, randomized controlled trials (RCTs) of antibiotic therapy for ABSSSI used broad trial inclusion criteria and utilized investigator-determined clinical resolution, 7 to 14 days after the end of therapy, as the primary outcome measure. In order to produce more objective, reproducible, and quantifiable primary outcome measures, the US Food and Drug Administration (FDA) Center for Drug Evaluation and Research and a multidisciplinary consortium convened by the Foundation for the National Institutes of Health (FNIH) issued significantly changed trial guidance criteria. The currently recommended primary outcome measure is an assessment of greater than 20% reduction in the area of erythema, edema, or induration from baseline, measured at 48 to 72 h after randomization and initiation of drug treatment. In contrast, the European Medicines Agency (EMA) still recommends measurement of clinical resolution at a later time period. We discuss the evolution of changes to trial guidance criteria issued by the FDA since 1998 and the potential difficulties of implementing the recommended primary outcome measured at an earlier time point in RCTs of outpatient antibiotic treatment performed in the ED setting.

[Systemic therapy with antibiotics. Overview of important antibiotics in dermatology]

BACKGROUND

Systemic antibiotics are used in a targeted fashion, i.e. according to antibiogram whenever possible, otherwise in a calculated or empiric way. The pathogen to be treated can be identified sometimes by the clinical symptoms (e.g. in classical erysipelas) or by microbiological analysis. The latter requires adequate sampling methods. Due to the demographic development, which entails age-related multimorbidity and polypharmacy, criteria for the selection of the correct antibiotic not only encompass the pathogen spectrum and the tissue penetration of the drug, but also the risks for adverse events and unwanted interactions with other drugs.

AIM

In this review article the mode of action, mechanisms of resistance, pharmacokinetics, adverse events, and drug interactions of the dermatologically important antibiotics are summarized, as are some relevant indications for their appropriate use in dermatology.

RESULTS

For most bacterial skin and soft tissue infections beta-lactam antibiotics represent the first line therapy. They are efficacious, their adverse events are well known and defined, and they are mostly cost-effective. Penicillins G and V are recommended for classical erysipelas (caused by hemolytic streptococci). For uncomplicated soft tissue infections originating from wounds, which are mostly due to Staphylococcus aureus, the first line therapy are cephalosporins group 1 and 2, or isoxazoyl penicillins. The use of broad-spectrum antibiotics is indicated only for complicated soft tissue infections when a different spectrum of bacterial pathogens is suspected or when (multi-) resistant bacteria are supposed to be the causative organism.

Cutaneous bacterial infections caused by Staphylococcus aureus and Streptococcus pyogenes in infants and children

Acute bacterial skin and skin structure infections (SSSIs) are among the most common bacterial infections in children. The medical burden of SSSIs, particularly abscesses, has increased nationwide since the emergence of community-acquired methicillin-resistant Staphylococcus aureus. SSSIs represent a wide spectrum of disease severity. Prompt recognition, timely institution of appropriate therapy, and judicious antimicrobial use optimize patient outcomes. For abscesses, incision and drainage are paramount and might avoid the need for antibiotic treatment in uncomplicated cases. If indicated, empiric antimicrobial therapy should target Streptococcus pyogenes for nonpurulent SSSIs, such as uncomplicated cellulitis, and S aureus for purulent SSSIs such as abscesses.

Antibiotic therapy for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) in non surgical wounds

BACKGROUND

Non surgical wounds include chronic ulcers (pressure or decubitus ulcers, venous ulcers, diabetic ulcers, ischaemic ulcers), burns and traumatic wounds. The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) colonisation (i.e. presence of MRSA in the absence of clinical features of infection such as redness or pus discharge) or infection in chronic ulcers varies between 7% and 30%. MRSA colonisation or infection of non surgical wounds can result in MRSA bacteraemia (infection of the blood) which is associated with a 30-day mortality of about 28% to 38% and a one-year mortality of about 55%. People with non surgical wounds colonised or infected with MRSA may be reservoirs of MRSA, so it is important to treat them, however, we do not know the optimal antibiotic regimen to use in these cases.

OBJECTIVES

To compare the benefits (such as decreased mortality and improved quality of life) and harms (such as adverse events related to antibiotic use) of all antibiotic treatments in people with non surgical wounds with established colonisation or infection caused by MRSA.

SEARCH METHODS

We searched the following databases: The Cochrane Wounds Group Specialised Register (searched 13 March 2013); The Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 2); Database of Abstracts of Reviews of Effects (2013, Issue 2); NHS Economic Evaluation Database (2013, Issue 2); Ovid MEDLINE (1946 to February Week 4 2013); Ovid MEDLINE (In-Process & Other Non-Indexed Citations, March 12, 2013); Ovid EMBASE (1974 to 2013 Week 10); EBSCO CINAHL (1982 to 8 March 2013).

SELECTION CRITERIA

We included only randomised controlled trials (RCTs) comparing antibiotic treatment with no antibiotic treatment or with another antibiotic regimen for the treatment of MRSA-infected non surgical wounds. We included all relevant RCTs in the analysis, irrespective of language, publication status, publication year, or sample size.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified the trials, and extracted data from the trial reports. We calculated the risk ratio (RR) with 95% confidence intervals (CI) for comparing the binary outcomes between the groups and planned to calculate the mean difference (MD) with 95% CI for comparing the continuous outcomes. We planned to perform the meta-analysis using both fixed-effect and random-effects models. We performed intention-to-treat analysis whenever possible.

MAIN RESULTS

We identified three trials that met the inclusion criteria for this review. In these, a total of 47 people with MRSA-positive diabetic foot infections were randomised to six different antibiotic regimens. While these trials included 925 people with multiple pathogens, they reported the information on outcomes for people with MRSA infections separately (MRSA prevalence: 5.1%). The only outcome reported for people with MRSA infection in these trials was the eradication of MRSA. The three trials did not report the review's primary outcomes (death and quality of life) and secondary outcomes (length of hospital stay, use of healthcare resources and time to complete wound healing). Two trials reported serious adverse events in people with infection due to any type of bacteria (i.e. not just MRSA infections), so the proportion of patients with serious adverse events was not available for MRSA-infected wounds. Overall, MRSA was eradicated in 31/47 (66%) of the people included in the three trials, but there were no significant differences in the proportion of people in whom MRSA was eradicated in any of the comparisons, as shown below.1. Daptomycin compared with vancomycin or semisynthetic penicillin: RR of MRSA eradication 1.13; 95% CI 0.56 to 2.25 (14 people).2. Ertapenem compared with piperacillin/tazobactam: RR of MRSA eradication 0.71; 95% CI 0.06 to 9.10 (10 people).3. Moxifloxacin compared with piperacillin/tazobactam followed by amoxycillin/clavulanate: RR of MRSA eradication 0.87; 95% CI 0.56 to 1.36 (23 people).

AUTHORS' CONCLUSIONS

We found no trials comparing the use of antibiotics with no antibiotic for treating MRSA-colonised non-surgical wounds and therefore can draw no conclusions for this population. In the trials that compared different antibiotics for treating MRSA-infected non surgical wounds, there was no evidence that any one antibiotic was better than the others. Further well-designed RCTs are necessary.

Skin and soft tissue infections

The approach to common skin and soft tissue infections (SSTIs) was previously well understood. However, the recent emergence of community-associated methicillin resistant Staphyloccocus aureus as a common pathogen has changed the epidemiology of these infections and has led clinicians to alter their practice and treatment of SSTI. This article discusses the present epidemiology of SSTI and community-acquired methicillin-resistant Staphylococcus aureus, evidence-based approach to incision and drainage, the utility of adjuvant antibiotic therapy after abscess drainage, and current antimicrobial approach to cellulitis and nondrained SSTIs. Methods to reduce transmission and recurrence of SSTI through decolonization strategies are also discussed.

Update on Epidemiology and Treatment of MRSA Infections in Children

In 2000-10 the epidemiology of pediatric MRSA infections in the United States was transformed with an epidemic of CA-MRSA infections. We review the epidemiology of MRSA in the community and in the health care setting, including intensive care units, among infants and CF patients, and in households as well as the impact that the CA-MRSA epidemic has had on hospitalization with MRSA infections. Risk factors for carriage, transmission, and initial and recurrent infection with MRSA are discussed. New studies on the treatment of pediatric MRSA infections and on the efficacy of MRSA decolonization are reviewed.

Abscess volume and ultrasound characteristics of community-associated methicillin-resistant Staphylococcus aureus infection

BACKGROUND

Skin abscesses may vary in volume and inflammation based on organism, although this has not been evaluated using emergency ultrasonography (EUS).

OBJECTIVE

The objective of this study was to examine the utility of EUS in discerning skin abscess volume and inflammation by infecting organism.

METHODS

This was a secondary analysis of prospectively enrolled subjects 2 months to 19 years presenting for a skin abscess. Subjects with a prior drainage procedure, multiple lesions, incomplete EUS measurements, or lack of an abscess culture were excluded. Abscess cavity dimensions in the x, y, and z planes and signs of local inflammation (cobblestoning, hyperechoic, or thickened dermis) were determined. Abscess volume was calculated using the ellipsoid formula: 4/3 π · (rx) · (ry) · (rz).

RESULTS

One hundred eighty-eight subjects met the inclusion criteria. Mean age was 7.7 ± 6.2 years; 39.9% were male. The gluteal region was most commonly involved (33.0%), and lesions were present for a mean 4.2 days (95% confidence interval [CI], 3.8-4.6 days). Methicillin-resistant Staphylococcus aureus (MRSA) was isolated from 125 (66.5%); methicillin-sensitive S. aureus (21.8%) was most common among non-MRSA lesions. Abscess volume was smaller in MRSA (1.12 cm3) compared with non-MRSA (2.46 cm3) lesions (mean difference, -1.33 cm; 95% CI, -2.21 to -0.47 cm3). No differences between MRSA and non-MRSA lesions were present for EUS signs of inflammation. When adjusting for age, duration of lesion, and spontaneous drainage, smaller abscess volumes were associated with MRSA infection (odds ratio, 0.83; 95% CI, 0.71-0.97). Using an optimal threshold value of 1.32 cm3, sensitivity and specificity for non-MRSA lesion were 50.8% and 81.5%, respectively.

CONCLUSIONS

Methicillin-resistant S. aureus infection is statistically negatively associated with abscess volume, although of limited predictive ability. Findings using EUS suggest that MRSA does not differ from other organisms with respect to size and inflammation. Clinicians should not consider unique treatment for the presence of MRSA abscess based on these EUS findings.

A prospective, multicenter, observational study of complicated skin and soft tissue infections in hospitalized patients: clinical characteristics, medical treatment, and outcomes

Background

Complicated skin and soft tissue infections (cSSTIs) occur frequently, but limited data do not allow any consensus on an optimal treatment strategy. We designed this prospective, multicenter, observational study to to explore the current epidemiology, treatment, and resulting clinical outcomes of cSSTIs to help develop strategies to potentially improve outcomes.

Methods

From June 2008 to December 2009 we enrolled a pre-specified number of adults treated in 56 U.S. hospitals with intravenous antibiotic(s) for any of the following cSSTIs: diabetic foot infection (DFI); surgical site infection (SSI); deep soft tissue abscess (DSTA); or, cellulitis. Investigators treated all patients per their usual practice during the study and collected data on a standardized form.

Results

We enrolled 1,033 patients (DFI 27%; SSI 32%; DSTA 14%; cellulitis 27%; mean age 54 years; 54% male), of which 74% had healthcare-associated risk factors. At presentation, 89% of patients received initial empiric therapy with intravenous antibiotics; ~20% of these patients had this empiric regimen changed or discontinued based on culture and sensitivity results. Vancomycin was the most frequently used initial intravenous antibiotic, ordered in 61% of cases. During their stay 44% of patients underwent a surgical procedure related to the study infection, usually incision and drainage or debridement. The mean length of stay was 7.1 days, ranging from 5.8 (DSTA) to 8.1 (SSI).

Conclusion

Our findings from this large prospective observational study that characterized patients with cSSTIs from diverse US inpatient populations provide useful information on the current epidemiology, clinical management practices and outcomes of this common infection.

Epidemiologic Similarities in Pediatric Community-Associated Methicillin-Resistant and Methicillin-Sensitive Staphylococcus aureus in the San Francisco Bay Area

BACKGROUND

Risk factors differentiating methicillin-resistant Staphylococcus aureus (MRSA) from methicillin-sensitive S aureus (MSSA) infections in the pediatric community have been unclear.

METHODS

We performed a prospective case-comparison investigation of clinical, epidemiological, and molecular factors in pediatric community-associated (CA) MRSA and MSSA cases in the San Francisco Bay Area. Chart reviews were conducted in 270 CA-MRSA and 313 CA-MSSA cases. Fifty-eight CA-MRSA (21.4%) and 95 CA-MSSA (30.4%) cases were interviewed. Molecular typing was performed on 111 isolates.

RESULTS

MSSA represented 53.7% of CA cases and was more likely to cause invasive disease (6.2% vs 1.1%, P = .004). Few potential epidemiologic risk factors distinguished CA-MRSA from CA-MSSA. No differences were found in factors related to crowding, cleanliness, or prior antibiotic use. Compromised skin integrity due to eczema (24.3% vs 13.5%, P = .001) was associated with CA-MSSA. Many exposures to potentially infected or colonized contacts or contaminated objects were assessed; only three were associated with CA-MSSA: having a household contact who had surgery in the past year (18.9% vs 6.0%, P = .02), and regular visits to a public shower (9.1% vs 2.0%, P = .01) or gym (12.6% vs 3.3%, P = .04). Molecular typing identified clonal complex 8 as the predominant genetic lineage among CA-MRSA (96.4%) and CA-MSSA (39.3%) isolates.

CONCLUSIONS

In the context of recent heightened focus on CA-MRSA, the burden of serious disease caused by CA-MSSA among children should not be overlooked. MRSA and MSSA may be growing epidemiologically similar; thus, research, clinical, and public health efforts should focus on S aureus as a single entity.

Empirical evaluation of age groups and age-subgroup analyses in pediatric randomized trials and pediatric meta-analyses

BACKGROUND

An important step toward improvement of the conduct of pediatric clinical research is the standardization of the ages of children to be included in pediatric trials and the optimal age-subgroups to be analyzed.

METHODS

We set out to evaluate empirically the age ranges of children, and age-subgroup analyses thereof, reported in recent pediatric randomized clinical trials (RCTs) and meta-analyses. First, we screened 24 RCTs published in Pediatrics during the first 6 months of 2011; second, we screened 188 pediatric RCTs published in 2007 in the Cochrane Central Register of Controlled Trials; third, we screened 48 pediatric meta-analyses published in the Cochrane Database of Systematic Reviews in 2011. We extracted information on age ranges and age-subgroups considered and age-subgroup differences reported.

RESULTS

The age range of children in RCTs published in Pediatrics varied from 0.1 to 17.5 years (median age: 5; interquartile range: 1.8-10.2) and only 25% of those presented age-subgroup analyses. Large variability was also detected for age ranges in 188 RCTs from the Cochrane Central Register of Controlled Trials, and only 28 of those analyzed age-subgroups. Moreover, only 11 of 48 meta-analyses had age-subgroup analyses, and in 6 of those, only different studies were included. Furthermore, most of these observed differences were not beyond chance.

CONCLUSIONS

We observed large variability in the age ranges and age-subgroups of children included in recent pediatric trials and meta-analyses. Despite the limited available data, some age-subgroup differences were noted. The rationale for the selection of particular age-subgroups deserves further study.

Interventions for impetigo

BACKGROUND

Impetigo is a common, superficial bacterial skin infection, which is most frequently encountered in children. There is no generally agreed standard therapy, and guidelines for treatment differ widely. Treatment options include many different oral and topical antibiotics as well as disinfectants. This is an updated version of the original review published in 2003.

OBJECTIVES

To assess the effects of treatments for impetigo, including non-pharmacological interventions and 'waiting for natural resolution'.

SEARCH METHODS

We updated our searches of the following databases to July 2010: the Cochrane Skin Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (from 2005), EMBASE (from 2007), and LILACS (from 1982). We also searched online trials registries for ongoing trials, and we handsearched the reference lists of new studies found in the updated search.

SELECTION CRITERIA

Randomised controlled trials of treatments for non-bullous, bullous, primary, and secondary impetigo.

DATA COLLECTION AND ANALYSIS

Two independent authors undertook all steps in data collection. We performed quality assessments and data collection in two separate stages.

MAIN RESULTS

We included 57 trials in the first version of this review. For this update 1 of those trials was excluded and 12 new trials were added. The total number of included trials was, thus, 68, with 5578 participants, reporting on 50 different treatments, including placebo. Most trials were in primary impetigo or did not specify this.For many of the items that were assessed for risk of bias, most studies did not provide enough information. Fifteen studies reported blinding of participants and outcome assessors.Topical antibiotic treatment showed better cure rates than placebo (pooled risk ratio (RR) 2. 24, 95% confidence interval (CI) 1.61 to 3.13) in 6 studies with 575 participants. In 4 studies with 440 participants, there was no clear evidence that either of the most commonly studied topical antibiotics (mupirocin and fusidic acid) was more effective than the other (RR 1.03, 95% CI 0.95 to 1.11).In 10 studies with 581 participants, topical mupirocin was shown to be slightly superior to oral erythromycin (pooled RR 1.07, 95% CI 1.01 to 1.13). There were no significant differences in cure rates from treatment with topical versus other oral antibiotics. There were, however, differences in the outcome from treatment with different oral antibiotics: penicillin was inferior to erythromycin, in 2 studies with 79 participants (pooled RR 1.29, 95% CI 1.07 to 1.56), and cloxacillin, in 2 studies with 166 participants (pooled RR 1.59, 95% CI 1.21 to 2.08).There was a lack of evidence for the benefit of using disinfectant solutions. When 2 studies with 292 participants were pooled, topical antibiotics were significantly better than disinfecting treatments (RR 1.15, 95% CI 1.01 to 1.32).The reported number of side-effects was low, and most of these were mild. Side-effects were more common for oral antibiotic treatment compared to topical treatment. Gastrointestinal effects accounted for most of the difference.Worldwide, bacteria causing impetigo show growing resistance rates for commonly used antibiotics. For a newly developed topical treatment, retapamulin, no resistance has yet been reported.

AUTHORS' CONCLUSIONS

There is good evidence that topical mupirocin and topical fusidic acid are equally, or more, effective than oral treatment. Due to the lack of studies in people with extensive impetigo, it is unclear if oral antibiotics are superior to topical antibiotics in this group. Fusidic acid and mupirocin are of similar efficacy. Penicillin was not as effective as most other antibiotics. There is a lack of evidence to support disinfection measures to manage impetigo.

Presence of genes encoding panton-valentine leukocidin is not the primary determinant of outcome in patients with hospital-acquired pneumonia due to Staphylococcus aureus

The impact of Panton-Valentine leukocidin (PVL) on the outcome in Staphylococcus aureus pneumonia is controversial. We genotyped S. aureus isolates from patients with hospital-acquired pneumonia (HAP) enrolled in two registrational multinational clinical trials for the genetic elements carrying pvl and 30 other virulence genes. A total of 287 isolates (173 methicillin-resistant S. aureus [MRSA] and 114 methicillin-susceptible S. aureus [MSSA] isolates) from patients from 127 centers in 34 countries for whom clinical outcomes of cure or failure were available underwent genotyping. Of these, pvl was detected by PCR and its product confirmed in 23 isolates (8.0%) (MRSA, 18/173 isolates [10.4%]; MSSA, 5/114 isolates [4.4%]). The presence of pvl was not associated with a higher risk for clinical failure (4/23 [17.4%] versus 48/264 [18.2%]; P = 1.00) or mortality. These findings persisted after adjustment for multiple potential confounding variables. No significant associations between clinical outcome and (i) presence of any of the 30 other virulence genes tested, (ii) presence of specific bacterial clone, (iii) levels of alpha-hemolysin, or (iv) delta-hemolysin production were identified. This study suggests that neither pvl presence nor in vitro level of alpha-hemolysin production is the primary determinant of outcome among patients with HAP caused by S. aureus.

Common childhood bacterial infections

Children with infectious diseases are commonly encountered in primary care settings. Identification of the subset of patients with bacterial infections is key in guiding the best possible management. Clinicians frequently care for children with infections of the upper respiratory tract, including acute otitis media, otitis externa, sinusitis, and pharyngitis. Conjunctivitis is not an uncommon reason for office visits. Bacterial pneumonia, urinary tract infections, and gastroenteritis are regularly seen. Over the last decade, a growing number of children have had infections of the skin and soft tissue, driven by the increased prevalence of infections caused by methicillin-resistant Staphylococcus aureus. The following review addresses the epidemiology and risk factors for specific infections and examines the clinical presentation and selection of appropriate diagnostic methods in such conditions. Methods to prevent these bacterial infections and recommendations for follow-up are suggested. Management of these infections requires that antimicrobial agents be used in a judicious manner in the outpatient setting. Such antibiotic therapy is recommended using both available clinical evidence and review of disease-specific treatment guidelines.