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

What is the diagnostic accuracy of neutrophil to lymphocyte ratio and monocyte to lymphocyte ratio in detecting acute periprosthetic joint infections? A gender-specific analysis

PURPOSE

The accurate and timely diagnosis of periprosthetic joint infection (PJI) is critical for guiding optimal treatment management and success, highlighting the requirement of readily available inexpensive serum biomarkers to increase the diagnostic accuracy for PJI. Many studies have investigated the diagnostic accuracy of neutrophil to lymphocyte ratio (NLR) and monocyte to lymphocyte ratio (MLR). However, there is a lack of existing literature regarding optimal thresholds for acute PJI. The purpose of this study was to reveal the most appropriate cut-off values for MLR and NLR in detecting acute PJI with a gender specific analysis.

METHODS

Patients were classified as having an acute PJI if they met the International Consensus Meeting (ICM) 2018 modified criteria. Patients who had a negative clinical and diagnostic workup for a PJI and the presence of erythema on the index surgical area were included in the erysipelas group (control group). Data obtained from all patients included age, sex, body mass index (BMI), Charlson Comorbidity Index (CCI), procedure type (THA or TKA), serum C-reactive protein (CRP), and blood studies at the admission and culture results were retrieved from the electronic medical record.

RESULTS

ROC curve analysis was used to determine the gender-specific optimal threshold values for CRP, NLR, and MLR. Comparing the sensitivities and specificities of NLR and MLR at the identified best thresholds in males and females, the study found similar sensitivities of NLR in males and females with 0.84 and 0.84, respectively. On the other hand, an MLR of 0.67 or more reported a notably higher specificity in male patients [0.90 (95% CI 0.75-0.96) versus 0.70 (95% CI 0.56-0.80)].

CONCLUSION

NLR and MLR represent commonly ordered, low-cost, simple, and readily available complete cell count laboratory values and should be used as adjunct tests with reasonable diagnostic accuracy in detecting acute PJIs. Moreover, with its excellent specificity and PPV, MLR could provide valuable insight in diagnosing acute PJI, particularly in male patients.

LEVEL OF EVIDENCE

Level III Retrospective Cohort analysis.

S1 guideline: Differential diagnosis of acute and chronic redness of the lower legs

Acute or chronic redness of the lower leg is a frequent reason for visits to clinics and practices. The differential diagnosis is often challenging. The aim of this guideline is to define criteria and procedures for the differential diagnosis of acute or chronic, unilateral or bilateral redness of the lower leg. Finding the correct diagnosis is essential for selecting an appropriate treatment and can help to reduce the inappropriate use of antibiotics. The guideline committee identified the most relevant differential diagnoses: 1. erysipelas, 2. stasis dermatitis, 3. hyperergic ictus reaction, 4. superficial and deep vein thrombosis, 5. gout, 6. chronic allergic contact dermatitis, and 7. acute toxic or allergic contact dermatitis. Algorithms/diagnostic pathways, each of which can be broken down into anamnesis, clinical examination, and diagnostics, have been developed for these seven diagnoses. In addition, the guideline group identified over 40 other relevant diagnoses and summarized their characteristics in a table to facilitate further differential diagnoses.

Risk factors of recurrent erysipelas in adult Chinese patients: a prospective cohort study

BACKGROUND

Erysipelas is a common skin infection that is prone to recur. Recurrent erysipelas has a severe effect on the quality of life of patients. The present study aimed to investigate the risk factors of recurrent erysipelas in adult Chinese patients.

METHODS

A total of 428 Chinese patients with erysipelas who met the inclusion criteria were studied. The patients were divided into the nonrecurrent erysipelas group and the recurrent erysipelas group. Clinical data were collected on the first episode and relapse of erysipelas. The patients were followed up every 3 months. Statistical analysis was performed to analyze and determine the risk factors of erysipelas relapse.

RESULTS

Univariate analysis was performed to analyze the data, including surgery, types of antibiotics administered in the first episode, obesity, diabetes mellitus, venous insufficiency, lymphedema, and malignancy. The differences between the groups were statistically significant (p < 0.05). The Cox proportional hazards regression model analysis showed that the final risk factors included surgery, obesity, diabetes mellitus, venous insufficiency, and lymphedema.

CONCLUSIONS

Surgery, obesity, diabetes mellitus, venous insufficiency, and lymphedema are considered as risk factors for recurrent erysipelas.