Atypical Presentation of Escherichia coli Monomicrobial Necrotizing Fasciitis in a Renal Transplant Patient: A Case Report

Impact of Comorbidities on the Cause of Death by Necrotizing Soft Tissue Infections

Background: The aim of this study was to identify the cause of death in patients with necrotizing soft tissue infections (NSTIs) stratified by patient's pre-existing comorbidities (American Society of Anesthesiologists [ASA] classification 3/4 vs. ASA 1/2). Differences in clinical presentation, mortality rate, and factors associated with mortality between those two comorbidity groups were investigated. Patients and Methods: A retrospective multicenter study of patients with NSTIs between 2010 and 2020 was conducted. The primary outcome was the cause of death within the first 30 days. Furthermore, factors associated with mortality were identified. All analysis were stratified by severity of comorbidities (ASA 1/2 or ASA 3/4). Results: Of the 187 patients, 39 patients (21%) died within 30 days. American Society of Anesthesiologists 1/2 patients (overall mortality rate, 11%) died more often as direct result of the infection compared with ASA 3/4 patients (overall mortality rate, 33%) (ASA 1/2 group: 92% vs. ASA 3/4 group: 48%; p = 0.013). American Society of Anesthesiologists 3/4 patients died more often due to withdrawal of life-sustaining therapies based on assumed poor outcome after severe critical illness (ASA 1/2 group: 52% vs. ASA 3/4 group: 8%; p = 0.013). Conclusions: Mortality rates of patients with NSTIs varied from 11% in previously healthy patients to 33% in patients with multiple or severe comorbidities. The predominant cause of mortality was overwhelming infection and associated sepsis in healthy patients whereas in patients with multiple or severe pre-existing medical disease, death most often occurred after treatment limitations based on patient's wishes and prognosis.

Necrotizing fasciitis caused by mono-bacterial gram-negative infection with E. coli - the deadliest of them all: A case series and review of the literature

Introduction

Unlike other skin and soft tissue infections, necrotizing fasciitis (NF) is a very rare but potentially fatal condition. Common organisms causing NF are poly-microbial (type I) infection with mixed organisms and mono-bacterial gram-positive infection with mainly streptococci (type II). Mono-bacterial gram-negative NF is a rare form of NF that is not included in the current classification.

Case series

We report four cases of mono-bacterial gram-negative NF caused by E. coli. All patients presented in septic shock and showed landscape-like skin necrosis and pain out of proportion. Radical debridement and escalation of antibiotic treatment was performed in all patients. Short-term survival was 50%. Two patients died of multiorgan failure. Two patients survived short term: One patient was amputated through the knee but died six months later of metastatic prostate cancer. One patient was covered with split thickness skin grafts and died three months later of catheter-associated sepsis with endocarditis.

Discussion

Recent findings suggest adding a type III fasciitis, which is caused by mono-bacterial gram-negative organisms. As patients are getting older with even more comorbidities, mono-bacterial gram-negative NF will be an increasing problem for physicians treating soft tissue and skin infections.

In oncologic diseases, liver cirrhosis, renal diseases or otherwise immunocompromised patients, mono-bacterial gram-negative NF with E. coli is underestimated. Therefore, in these patients, antibiotic treatment should cover Gram-negative organisms including E. coli. However even with adjusted antibiotic treatment and radical debridement, the short-term survival and long-term outcome are poor.

A Rare Presentation of Escherichia coli Necrotizing Fasciitis in Renal Transplantation

Necrotizing fasciitis is a devastating, rapidly pro-gressive soft tissue infection. We present an unusual case of Escherichia coli necrotizing fasciitis following renal transplant. The patient was a 50-year-old woman previously on long-term hemodialysis who presented with left thigh erythema adjacent to the site of a central venous catheter 5 days after renal transplant. The classical features of necrotizing fasciitis were initially absent, and, despite aggressive resuscitation and debridement, she did not survive. Monomicrobial E. coli necrotizing fasciitis is rare, especially in this cohort of patients. Immunosuppression is a known risk factor for infection, and patients may present atypically. Shock and erythema may be the only clues to infection. Necrotizing fasciitis must be considered in acutely unwell renal transplant recipients so that immediate and life-saving surgical debridement can be delivered.