Serum Procalcitonin Level Reflects the Severity of Cellulitis

Complicated and deep bacterial skin and soft tissue infections

Complicated erysipelas, cellulitis, and necrotizing soft tissue infections belong to the spectrum of bacterial infections affecting the skin and underlying soft tissues. Their frequency as well as risk of recurrence and complicated disease course pose a significant health burden. The latter is further impacted by global travel activity, associated variations in the prevalence of microbes, the emergence of multi-resistant bacteria, demographically driven aging with an increase in critical comorbidities, immunosuppressive therapies, and excessive (including non-medical) use of antibiotics. Against this background, early and accurate diagnosis and promptly initiated therapeutic measures are major determinants in prognosis and clinical outcome. Diagnostic evaluation involves clinical, laboratory, microbiological, and radiographic findings, which are assessed in the context of patient-specific risk factors and comorbidities. First and foremost, given the indication, exploratory incisions of lesional tissue should be performed, allowing rapid assessment of the extent of tissue necrosis and providing guidance on the scope and extent of further (surgical and non-surgical) treatment modalities. Thus, delayed or inadequate interventions can be avoided, which reduces the duration of treatment, health expenses, the risk of recurrent hospitalizations, and mortality rates.

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.

Clinical and Laboratory Parameters for Differential Diagnosis of Necrotizing Faciitis and Cellulitis

ObjectiveS

Necrotizing fasciitis (NF) requires surgical intervention and has high morbidity and mortality. Furthermore, it can be confusing with some skin diseases such as cellulitis. We investigated the roles of clinical and laboratory parameters at the time of admission to the hospital in the differential diagnosis of NF and cellulitis patients.

Methods

Patients with cellulitis and NF located between the nipple level and the knee between January 2018 and January 2021 were included in our retrospective study. The fever, history, complete blood count results, blood biochemistry, C-reactive protein and procalcitonin values of the patients at the time of admission to the emergency department, length of hospital stay, mortality rates, and laboratory risk indicator for necrotizing fasciitis (LRINEC) scores were recorded and evaluated whether there was a difference in both patient groups.

Results

A total of 55 patients, including 26 patients in the NF group and 29 patients in the cellulite group, were included in the study. It was observed that patients with NF applied to the hospital statistically earlier, had higher leukocyte, platelet and neutrophil levels, had longer hospital stays and had higher mortality numbers.

Conclusion

In high leukocyte, platelet, and neutrophil levels in the case of cellulitis patients, the clinician should follow the patient's clinic course closely and keep NF in mind.

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.

Utility of Inflammatory Markers in Hospitalized Children With Skin Erythema

BACKGROUND

There is overlap in the clinical presentations of superficial skin infections (eg, cellulitis) and deeper infections (eg, osteomyelitis). Inflammatory markers are frequently obtained in hospitalized patients with cellulitis. However, it is unknown whether inflammatory markers discriminate between superficial and deeper infections.

METHODS

We performed a retrospective review of children hospitalized with erythema on the skin and diagnoses of cellulitis, bursitis, myositis, osteomyelitis, and/or tenosynovitis. Patients were grouped into superficial infection (cellulitis and bursitis) and deeper infection (myositis, tenosynovitis, osteomyelitis). We compared C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) values between the two groups and constructed receiver operating characteristic curves to determine optimal cutoff values.

RESULTS

Among 168 children hospitalized with skin erythema, 122 patients had superficial and 46 patients had deeper infections. Mean CRP and ESR were significantly higher in patients with deeper infections (CRP: 8.3 [±9.6] mg/dL versus 2.8 [±3.5] mg/dL; P < .001; ESR: 48.3 [±28.6] mm/h versus 21.8 [±16.0] mm/h; P < .001). Neither WBC nor fever was significantly different between groups. CRP ≥2 mg/dL and ESR ≥30 mm/h were associated with deeper infections (CRP: odds ratio: 4.77; 95% confidence interval: 2.24-10.15; ESR: odds ratio: 7.93; 95% confidence interval: 3.46-17.67). When CRP and ESR were below these cutoffs, the negative predictive value was 89%.

CONCLUSIONS

Among patients presenting with skin erythema, CRP ≥2 mg/dL and ESR ≥30 mm/hr were significantly associated with deeper infection, whereas values below these cutoffs were reassuring against deeper infection. Future study of inflammatory markers in skin and soft tissue infections may help develop tailored testing strategies.

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.

The rash that presents as a red swollen face

A red swollen face can be a skin sign of a potentially life-threatening condition. We present in detail the main clinical presentations, diagnostic tests, and management of some of the most severe conditions that can frequently present as a red and swollen face: acute or recurrent angioedema, mast cell-driven or bradykinin-mediated angioedema, nonhereditary and hereditary angioedema, allergic or photoallergic facial contact dermatitis, contact urticaria, severe adverse drug reactions (particularly drug reaction with eosinophilia and systemic symptoms [DRESS]), skin infections (erysipelas, cellulitis, necrotizing fasciitis), and autoimmune diseases (dermatomyositis). There are many other conditions that also have to be considered in the differential diagnosis of a red swollen face.

Time Course of C-Reactive Protein and Procalcitonin Levels During the Treatment of Acute Bacterial Skin Infections

In a pilot study of 22 patients with an acute bacterial skin infection, serum levels of C-reactive protein and procalcitonin tended to be elevated at presentation and declined within 3–5 days of treatment. Further study of a biomarker-guided treatment strategy to reduce antibiotic overuse in skin infections is warranted.