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

A sex-based analysis of complete blood count features during acute, untreated Lyme disease

Introduction

Although lymphopenia has been described in acute Lyme disease (LD), the complete blood count (CBC) has not been comprehensively examined, nor have sex-based analyses been conducted. We analyzed CBC values and identified sex-based trends among patients with early LD by comparing both to controls without a history of LD and to patients' pre-morbid values.

Methods

We enrolled participants from the Mid-Atlantic US with diagnostic erythema migrans and controls with no history of LD. CBC results were obtained, and patient information was recorded using standardized instruments. We also calculated a neutrophil-to-lymphocyte ratio (NLR). We used linear regression to test that CBC results would differ (a) between antibiotic-naive patients with early LD and controls and (b) by measures of acute disease severity. We also performed stratified analyses to assess sex-based differences.

Results

In total, 236 antibiotic-naive patients with early LD had significantly lower lymphocytes (β = -0.34, p < 0.001) and significantly higher monocytes (β = 0.09, p = 0.002) and NLRs (β = 0.99, p < 0.001) than 61 controls in adjusted analyses. Lymphocytes, monocytes, and NLRs also changed significantly from pre-morbid to acute LD (p < 0.001 for all). Only the NLR was consistently significantly associated with disease severity. A higher proportion of male patients with early LD had acute lymphopenia than female patients with early LD (31.93% vs. 19.66%, p = 0.03); this difference was not present among controls.

Conclusion

The presence of lymphopenia and the absence of an elevated total white blood cell count make LD an important diagnostic consideration in patients presenting with undiagnosed infectious syndromes in endemic regions. This may be especially true for male patients.

Factors and clinical prediction score for complication development after cellulitis diagnosis in adult patients

BACKGROUND

Cellulitis is defined as a bacterial infection of the skin and subcutaneous tissue that can cause multiple complications, such as sepsis and necrotizing fasciitis. In extreme cases, it may lead to multiorgan failure and death. We sought to analyze the clinical factors that contribute to the development of complicated disease, including demographics, clinical presentation, initial vital signs, and laboratory studies.

METHODS

Our study is a retrospective cohort study carried out in a university-based tertiary care hospital in Bangkok, Thailand. Adult patients who presented with cellulitis from January 1, 2018, to December 31, 2022, were evaluated for eligibility and inclusion in this study. All related variables for both outcomes, bacteremia and necrotizing fasciitis, were gathered from electronic medical records and analyzed using multivariable logistic regression analysis.

RESULTS

Of the 1,560 visits to this hospital, 47 cases reported at least one complication, with bacteremia noted in 27 visits (1.73%) and necrotizing fasciitis in 20 visits (1.27%). From the multivariable logistic regression analysis, six variables emerge as predictors of cellulitis complications. These are: Age ≥ 65 years, Body Mass Index ≥ 30 kg/m2, diabetes mellitus, body temperature ≥ 38 °C, systolic blood pressure ≤ 100 mmHg, and involvement of lower extremities. The predictive score was developed from these factors and was named the Ramathibodi Necrotizing Fasciitis/Bacteremia (RAMA-NFB) Prediction Score. Our predictive score has an accuracy of 82.93% (95% CI, 0.77-0.89). Patients in the high-risk group (RAMA NFB score > 6) have a likelihood ratio of 8.75 (95% CI, 4.41-18.12; p < 0.001) times to develop complications of cellulitis.

CONCLUSION

In our study, the RAMA-NFB Prediction Score predicts complications of necrotizing fasciitis and bacteremia in adult patients who present with cellulitis. External validation of this predictive score is still needed for further practical application.

Prognostic Significance of NLR, LMR, PLR, and CRP-Albumin Ratio in Lower Extremity Cellulitis: A Hospitalization and Recurrence Analysis

Cellulitis, an inflammatory disease of the skin and subcutaneous tissue caused by bacterial agents, frequently causes lower-extremity wounds. Many new biomarkers have been introduced to aid the diagnosis of inflammatory diseases. In this study, we aimed to evaluate the risk of recurrence of lower-extremity cellulitis wounds and the factors determining the need for hospitalization. Demographic characteristics and underlying diseases of the patients, white blood cell count, neutrophil, lymphocyte, monocyte, neutrophil, lymphocyte, lymphocyte and monocyte counts at admission, white blood cell count at admission, platelet count, total protein, albumin, erythrocyte sedimentation rate, C-reactive protein (CRP), procalcitonin level, neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), platelet-to-lymphocyte ratio (PLR), and CRP/albumin ratio were evaluated. Of the 132 patients with lower extremity cellulitis wounds, the median age was 56 years (range, 20-96 years), and 88 (66.7%) were male. Diabetes mellitus was the most commonly associated systemic disease. The most common symptom (97%) was a rash. Of the patients, 80 (60.6%) were hospitalized and 52 (39.4%) were treated as outpatients. Seventeen (12.9%) patients had recurrent cellulitis. While comorbidities and increased lesion size increased the risk in patients with recurrent cellulitis, median platelet count (P = .010), D-dimer level (P = .036), and CRP-Alb ratio (P = .019) were higher. Particularly increased lesion size, platelet count, total protein, and CRP levels should be a warning to clinicians in terms of the need for hospitalization and the risk of recurrence in patients with cellulite. In our study, PLR and CRP/albumin ratios were found to be high in these patient groups, and determining the usefulness of new biomarkers through new studies will give us a new perspective in clinical practice.