Beta-Hemolytic Streptococci and Necrotizing Soft Tissue Infections.

ß-hemolytic streptococci are major causes of necrotizing soft tissue infections (NSTIs), Streptococcus pyogenes (group A streptococcus; GAS) in particular. NSTIs caused by Streptococcus dysgalactiae (SD) have also been reported. In the INFECT cohort of 409 NSTIs patients, more than a third of the cases were caused by GAS (31%) or SD (7%). Risk factors of streptococcal NSTIs compared to streptococcal cellulitis have previously been largely unknown. The INFECT study confirmed blunt trauma as an important risk factor. In addition, absence of pre-existing skin lesions and a lower BMI were associated with NSTIs. The study also confirmed that septic shock is more frequent in GAS cases than in other types of NSTIs. Septic shock was also among several predictors of mortality. The role of intravenous immunoglobulin (IVIG) in streptococcal NSTIs has been unclear. In the INFECT cohort, IVIG treatment was associated with increased survival. As in other studies, a significant microbial diversity was observed, but with predominance of a few emm types. Overall, the INFECT study gives a comprehensive and contemporary picture of the clinical characteristics and the microbes involved in streptococcal NSTIs. The reported severity of disease underscores the need for new efforts aimed at identifying novel diagnostic measures and improved treatment.

Evaluation of laboratory risk indicator for necrotizing fasciitis score as an early diagnostic tool for necrotizing fasciitis: a prospective observational study.

Introduction: From its historical identification to modern times with advancements in management modalities globally, the mortality of necrotizing fasciitis (NF) is high ranging from 19 to 30% for all affected sites. Although many diagnostic adjuncts have been developed to assist with the prompt and accurate diagnosis of NF, the primary diagnosis is still based on high clinical suspicion. The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score was developed as a tool for distinguishing NF from other soft tissue infections. The main objective of this study is to evaluate LRINEC as a tool for early diagnosis of NF and differentiating it from other soft tissue infections like cellulitis. Methods: This is a single-centered, prospective observational study. Patients presenting with soft tissue infections of the limbs to the emergency department from November 2020 to October 2021 were included in this study. The clinical findings and blood parameters for the LRINEC score were collected and the score was calculated. Based on clinical suspicion of NF, patients underwent debridement and had a tissue biopsy to confirm the diagnosis. The data obtained was analyzed using SPSS version 24 and MS Excel. The AUC curve was used to calculate a cutoff, sensitivity, specificity, positive predictive value, and negative predictive values for the LRINEC score based on our study. Results: Forty-five patients with 28 males and 17 females were included. The average age was 53.667 years within a range of 19-79 years. Among them 44.4% of the patients had NF and 66.6% had other minor forms of soft tissue infections. The ROC curve obtained a cutoff value of greater than or equal to 6, with an AUC of 0.751. At this cut of value study showed a sensitivity of 85% with a specificity of 52%. Similarly, positive predictive value was found to be 58.62%, negative predictive values of 81.25%, and overall accuracy of 66.67% in early diagnosis of NF. Conclusion: In conclusion, our study showed that the LRINEC score can be a reliable tool for the early diagnosis of NF in an ED setting. This scoring system is best to be used to rule out NF.

Necrotizing Soft Tissue Infections, the Challenge Remains.

Background: Necrotizing Soft Tissue Infections (NSTIs) are uncommon rapidly spreading infection of the soft tissues for which prompt surgical treatment is vital for survival. Currently, even with sufficient awareness and facilities available, ambiguous symptoms frequently result in treatment delay. Objectives: To illustrate the heterogeneity in presentation of NSTIs and the pitfalls entailing from this heterogeneity. Discussion: NSTI symptoms appear on a spectrum with on one side the typical critically ill patient with fast onset and progression of symptoms combined with severe systemic toxicity resulting in severe physical derangement and sepsis. In these cases, the suspicion of a NSTI rises quickly. On the other far side of the spectrum is the less evident type of presentation of the patient with gradual but slow progression of non-specific symptoms over the past couple of days without clear signs of sepsis initially. This side of the spectrum is under represented in current literature and some physicians involved in the care for NSTI patients are still unaware of this heterogeneity in presentation. Conclusion: The presentation of a critically ill patient with evident pain out of proportion, erythema, necrotic skin and bullae is the classical presentation of NSTIs. On the other hand, non-specific symptoms without systemic toxicity at presentation frequently result in a battery of diagnostics tests and imaging before the treatment strategy is determined. This may result in a delay in presentation, delay in diagnosis and delay in definitive treatment. This failure to perform an adequate exploration expeditiously can result in a preventable mortality.

The mythos of laudable pus along with an explanation for its origin.

The presence of pus is one of the most easily recognizable signs of an infection. However, for several centuries suppuration, known as 'laudable pus,' was believed to be a sign of a healthy, healing wound. This historical misconception can be explained by the difference in the presentation of a necrotizing soft tissue infection versus other more common skin and soft tissue infections. Chronic wound infections, due to pyogenic bacteria, typically produce large amounts of thick, whitish-yellow pus. On the other hand, necrotizing soft tissue infections, despite their severe mortality and morbidity, are devoid of pus in the traditional sense. What the ancient medical observers recognized was the fact that pus is not characteristic of this subset of incredibly severe infections. This is an important distinction to remember when evaluating an infection, even today.