Procalcitonin and cellulitis: correlation of procalcitonin blood levels with measurements of severity and outcome in patients with limb cellulitis

Diagnosis and Management of Hand Infections

Hand and upper-extremity infections span a broad spectrum of presentations for the hand surgeon, primary care provider, and emergency medicine practitioner. As many hand infections arise from penetrating trauma, knowledge of the offending pathogen, location, and mode of spread allows the clinician to determine the appropriate intervention. Along with a thorough history and physical examination, patient factors such as age, occupation, medical comorbidities, and surgical history should be noted. Timely diagnosis and appropriate management allow for optimal recovery and outcomes. In this article, we describe the ongoing debate regarding the timing and influence of preoperative antibiotics on culture yield, timing of debridement for open fractures as it relates to infection risk, and strategies for obtaining adequate cultures to guide antibiotic therapy for complex infections such as periprosthetic joint and hardware infections. Given the changing epidemiological landscape and increased rates of antibiotic resistance, it is critical to promote antibiotic stewardship. We provide updated treatment recommendations and antibiotic profiles for the treatment of common hand infections. Finally, we discuss newer technologies such as next-generation sequencing and development of promising diagnostic and treatment strategies that will enhance the hand surgeon's ability to treat complex hand infections.

Biomarker for infection in children with decompensated chronic liver disease: Neutrophilic CD64 or procalcitonin?

OBJECTIVE

Biomarkers with high accuracy for identification of infection in decompensated chronic liver disease (DCLD) are urgently needed. We compared the accuracy of neutrophilic cluster of differentiation 64 (nCD64) with procalcitonin for diagnosis of bacterial infection in children with DCLD.

METHODS

Consecutive children admitted with DCLD were enrolled prospectively. nCD64 was assessed by flow cytometry and expressed in percentage. nCD64, procalcitonin and hemogram were measured at admission and 7-14 days after treatment in those with infection. Complete work-up for infection was done. Presence, site and severity of infection was classified as per guidelines.

RESULTS

107 children [64 boys, age 97(18-168) months] were enrolled. 78(72.9%) had infection, 26(24%) had severe sepsis and 60(56%) had systemic inflammatory response syndrome. The commonest site of infection was ascitic fluid (n=37), followed by pneumonia (n=24), urinary tract (n=15), bacteraemia (n=10), cholangitis (n=8) and cellulitis (n=3). nCD64 (cut-off-51%, AUC-0.82) had a higher sensitivity (79.5%) and specificity (82.8%) than procalcitonin (cut-off ≥0.58ng/mL, AUC-0.74, sensitivity-76.9% and specificity-62.1%) for diagnosis of infection. nCD64 and procalcitonin correlated with infection severity, being highest in children with severe sepsis [88(71-97) %and 1.98(0.83-10.36) ng/mL], than in infection alone [72(45-84) % and 1.09(0.45-2.07) ng/mL], and no-infection [36(20.2-48) % and 0.42(0.19-1.08) ng/mL]. There was no difference in diagnostic utility of procalcitonin or nCD64 with different sites of infection. Elevation of all 3 parameters (nCD64, PCT and total leukocyte count) was uncommon but highly specific for presence of infection.

CONCLUSION

nCD64 identifies infection better than procalcitonin and correlates well with infection severity in children with DCLD.

A Quality Improvement Initiative to Reduce Duplicate Inflammatory Marker Use

Introduction

Inflammatory markers (IMs) are often ordered in multiples, even though evidence suggests that this does not add any clinical benefit. The project aimed to reduce the number of duplicate IMs for patients by 10% in 12 months.

Methods

We implemented a quality improvement (QI) project at our hospital, focusing on patients admitted to the pediatric hospital medicine service. The team chose the model for improvement as the QI methodology. Key interventions included ongoing provider education, integrating the project into the physician incentive plan, and reviewing disease-specific pathways. The primary outcome measure was "duplicate IM use," which was defined as any two or more IMs (procalcitonin, C-reactive protein, or erythrocyte sedimentation rate) obtained on the same patient within 24 hours. The secondary outcome measure was any IM use during their stay, and the balancing measures were average complete blood count use, hospital length of stay, and 7-day readmission rate.

Results

The baseline duplicate IM use, and any IM use was 43% and 19%, respectively. After the start of this QI project, duplicate IM use decreased to 12%, and the use of any IM also decreased to 12%. Complete blood count use varied from 11% to 24% during the project without obvious correlation to IM use. Hospital length of stay decreased from 2.5 to 2.6 days, and the 7-day readmission rate remained at 2.8%.

Conclusions

The duplicate IM use and IM use were decreased without a concurrent increase in the balancing measures, indicating that a safe reduction of IM testing is feasible in inpatient pediatric care.

Emerging Roles of Graphitic Carbon Nitride-based Materials in Biomedical Applications

Graphite carbon nitride (g-C3N4) is a two-dimensional conjugated polymer with a unique energy band structure similar to graphene. Due to its outstanding analytical advantages, such as relatively small band gap (2.7 eV), low-cost synthesis, high thermal stability, excellent photocatalytic ability, and good biocompatibility, g-C3N4 has attracted the interest of researchers and industry, especially in the medical field. This paper summarizes the latest research on g-C3N4-based composites in various biomedical applications, including therapy, diagnostic imaging, biosensors, antibacterial, and wearable devices. In addition, the application prospects and possible challenges of g-C3N4 in nanomedicine are also discussed in detail. This review is expected to inspire emerging biomedical applications based on g-C3N4.

Overview of Pediatric Procalcitonin Testing Patterns in a Tertiary Care Children's Hospital

The use of procalcitonin (PCT) has grown over the past decade with increasing reliance on the test to rule out bacterial infection. We retrospectively reviewed the medical records of children <18 years old hospitalized at a tertiary care children's hospital from 2017 to 2019 who had PCT testing performed during their admission. Of 4135 PCT levels collected on 1530 children, 982 (23.7%) were diagnostically low and 1993 (48.1%) were diagnostically elevated. Pediatric intensive care, with 6% of total hospital patients, obtained 41.4% of tests. Thirty-one (2%) patients had an average of 27 PCT levels per patient, accounting for 20% of all tests. Many children had symptoms for which testing is not indicated (eg, skin complaints). The differences in PCT testing by service, inappropriate patterns of repeat testing, and testing performed in patients for whom it is not indicated may identify targets for diagnostic stewardship.

Role of Procalcitonin for Early Discrimination Between Necrotizing Fasciitis and Cellulitis of the Extremities

Introduction Necrotizing fasciitis (NF) is a grave and life-threatening infection of the soft tissues. It is defined by the gradual necrosis of the fascia and subcutaneous tissue, which spreads along the fascial planes. Cellulitis, a prevalent skin infection, has led to suggestions that procalcitonin could serve as a diagnostic tool to distinguish it from other inflammatory skin conditions that resemble cellulitis. The study aims to assess the procalcitonin (PCT) levels in individuals with NF and cellulitis and determine its effectiveness in early differentiation between these two conditions. Methods After obtaining clearance from the institutional ethical committee, the study was conducted in the Department of General Surgery, Sri Devaraj Urs Medical College, over six months. Informed consent was obtained from all 30 patients included in this study. The study compared PCT levels in patients diagnosed with NF and cellulitis. Statistical analysis was performed using SPSS version 22 software (IBM Corp., Armonk, NY, USA). Results The mean age of subjects was 53.23 ± 8.78 years. Among patients, 21 (70%) were diagnosed with cellulitis and 9 (30%) were diagnosed with NF. The mean PCT levels were 0.34 ± 0.32 and 4.89 ± 1.98 among the cellulitis and NF groups, respectively. There was a significant difference (p<0.05). PCT had a sensitivity of 100% and a specificity of 100%, in differentiating cellulitis and necrotizing fasciitis. Conclusion PCT levels were notably elevated in cases of NF compared to cellulitis. Despite the study's limited sample size, it represents the first report highlighting the value of PCT as an early diagnostic tool for identifying necrotizing fasciitis.

Eczema Herpeticum Misdiagnosed as Facial Cellulitis in an African American Male

Eczema herpeticum (EH) is a cutaneous manifestation of disseminated herpes simplex virus, commonly observed in patients with active eczema. The condition often presents with systemic symptoms, including fever and fatigue, alongside vesiculopustular skin lesions. This case report describes a 19-year-old male with active eczema who was misdiagnosed with facial cellulitis in the emergency and inpatient setting in a community tertiary hospital. With worsening rash and development of ocular symptoms, the diagnosis was reconsidered to be more consistent with EH with herpetic keratitis, which improved with antiviral treatment. This report shows the significance of maintaining a high index of suspicion for EH in patients with eczema and the potential consequences of misdiagnosis and delay in treatment. It aims to enhance clinician awareness of EH and promote a broader differential for unusual presentations of common dermatological and ophthalmologic conditions, especially when caring for patients with limited access to specialist evaluation.

Extra-pulmonary applications of procalcitonin: an updated literature review

INTRODUCTION

: Procalcitonin (PCT) is a biomarker with established performance in the differentiation between bacterial and viral infections, predominantly in pulmonary infections, as well as the diagnosis and prognosis of bacterial sepsis. However, the role of PCT in extra-pulmonary infections is not well described.

AREAS COVERED

: We reviewed the role of PCT in commonly experienced extra-pulmonary infections including meningitis, diabetic foot infection, prosthetic joint infection, osteomyelitis, and skin and soft tissue infection. PubMed and Medline online libraries were searched, from 2013 till 2022, for relevant articles.

EXPERT OPINION

: For meningitis, PCT could distinguish bacterial from viral meningitis. PCT distinguished septic arthritis from different types of arthritis but had variable performance in discriminating septic arthritis from crystal arthropathy. For periprosthetic joint infections, results were inconclusive. PCT had a potential role in diagnosis of more complex infections such as osteomyelitis and diabetic foot infections, but further studies are needed for a definitive cutoff. In skin and soft tissue infections, PCT performance was more variable requiring further investigation to define cutoff for the discrimination of cellulitis from necrotizing fasciitis. We find that PCT performed best for meningitis and helps in the reduction of unnecessary antibiotic treatment, but has variable outcomes with other extra-pulmonary infections.

Surgical Infection Society 2020 Updated Guidelines on the Management of Complicated Skin and Soft Tissue Infections

Background: The Surgical Infection Society (SIS) Guidelines for the treatment of complicated skin and soft tissue infections (SSTIs) were published in October 2009 in Surgical Infections. The purpose of this project was to provide a succinct update on the earlier guidelines based on an additional decade of data. Methods: We reviewed the previous guidelines eliminating bite wounds and diabetic foot infections including their associated references. Relevant articles on the topic of complicated SSTIs from 2008-2020 were reviewed and graded individually. Comparisons were then made between the old and the new graded recommendations with review of the older references by two authors when there was disparity between the grades. Results: The majority of new studies addressed antimicrobial options and duration of therapy particularly in complicated abscesses. There were fewer updated studies on diagnosis and specific operative interventions. Many of the topics addressed in the original guidelines had no new literature to evaluate. Conclusions: Most recommendations remain unchanged from the original guidelines with the exception of increased support for adjuvant antimicrobial therapy after drainage of complex abscess and increased data for the use of alternative antimicrobial agents.

Distinguishing Cellulitis from Its Noninfectious Mimics: Approach to the Red Leg

Cellulitis is a common clinical diagnosis in the outpatient and inpatient setting; studies have demonstrated a surprisingly high misdiagnosis rate: nearly one-third of cases are other conditions (ie, pseudocellulitis). This high rate of misdiagnosis is thought to contribute to nearly $515 million in avoidable health care spending in the United States each year; leading to the delayed or missed diagnosis of pseudocellulitis and to delays in appropriate treatment. There is a broad differential diagnosis for pseudocellulitis, which includes inflammatory and noninflammatory conditions of the skin. Accurate diagnosis of the specific condition causing pseudocellulitis is crucial to management, which varies greatly.

Diagnostic value of laboratory parameters for the discrimination between erysipelas and limited cellulitis

BACKGROUND AND OBJECTIVES

Erysipelas, caused by beta-hemolytic streptococci, and limited cellulitis, frequently caused by Staphylococcus aureus or other bacteria, are skin and soft tissue infections characterized by typical clinical signs. However, despite the therapeutical relevance they are often not differentiated (e.g in clinical trials). Erysipelas are efficiently treated with penicillin, while limited cellulitis is treated with more wide-spectrum antibiotics. This study investigates whether parameters such as CRP, blood counts or novel parameters like immature granulocytes could serve as biomarkers to distinguish between these entities.

PATIENTS AND METHODS

For this retrospective analysis 163 patients were included. We compared laboratory markers in patients with erysipelas (n = 68) to those with limited cellulitis (n = 41) of the leg. Both erysipelas and limited cellulitis were defined clinically, with an additional aspect for erysipelas being a prompt response to penicillin.

RESULTS

Erysipelas were characterized by higher levels of inflammation. CRP and leukocyte counts are the best parameters to discriminate between both infections. A CRP value ≥ 3.27 mg/dl indicated the diagnosis of erysipelas with 75 % sensitivity and 73.2 % specificity.

CONCLUSIONS

Our results support the thesis that erysipelas and limited cellulitis are distinct infections as defined in the German guidelines and that an assessment of CRP and leukocytes is useful for differential diagnosis.