Comparison of Clinical Characteristics and Outcomes between Idiopathic and Secondary Necrotizing Fasciitis in Streptococcal Infections -- A Single-Center Retrospective Study

鏈球菌引起之特異性與繼發性壞死性筋膜炎的臨床特徵及預後比較──單一醫療機構回溯性研究

Chun-Yang Kuo(郭淳仰)；Wen-Chung Liu(劉文忠)；Kuo-Chung Yang(楊國強)；Lee-Wei Chen(陳理維)

streptococcal infection ； idiopathic necrotizing fasciitis ； etiology ； prognosis

臺灣整形外科醫學會雜誌

33卷3期（2024 / 09 / 01）

255 - 273

英文;繁體中文

Background: Early recognition and prompt management of necrotizing fasciitis (NF) is the determining factor for optimizing outcomes. Delay of diagnosis is problematic and usually leads to inappropriate treatment and potentially serious consequences. This situation probably occurred when no inciting factors are identified. NF in the absence of inciting factors is considered to be idiopathic, whereas NF occurring in patients with a known causative factor is secondary NF. NF caused by streptococcal infections are able to spread rapidly regardless of age and overall health, leading to widespread necrosis of the subcutaneous tissues and will progress to sepsis and ultimately become fatal. When in terms of difficulty for early diagnosis and management of necrotizing fasciitis, it is crucial to consider that idiopathic NF exists clinically as a distinct entity. Aim and Objectives: The patients with necrotizing fasciitis caused by streptococcal infection were classified based on the route of infection into two groups: idiopathic and secondary NF. The study was designed to identify the specific features of idiopathic streptococcal NF and to uncover those that may facilitate early recognition and improved outcomes. Materials and Methods: This is a single-center retrospective study from January 1, 2013 to December 31, 2019. Patients were included based on positive serology or wound culture reports for streptococci. The records of 49 streptococcus (+) patients with pathologically confirmed NF were reviewed. We recorded data from each chart including the route of infection, demographics, comorbid conditions, microbiology, hematology, number of surgical procedures, duration from the onset of symptoms to the operation and clinical outcomes. The patients were then delegated to two groups based on the inciting factors being established, secondary NF, or not identified, idiopathic NF, and compared. Univariate and multivariate analyses and receiver operating characteristic curve analyses were performed. Results: 49 streptococcus (+) patients were identified as having NF. Two cases were excluded due to the lack of supporting findings to confirm the diagnosis of NF. Of the remaining 47 patients, 25 (53%) were designated as idiopathic NF, and the secondary group had 22 patients (47%). Comparative statistical analysis of the two groups revealed that the idiopathic group was statistically younger and had higher qSOFA scores (0.84 ± 0.9 vs. 0.32 ± 0.6, p = 0.031), higher C-reactive protein levels (25.99mg/dL vs. 19.59mg/dL, p = 0.046), and higher blood lactate levels (3.5mg/dL vs. 1.58mg/dL, p = 0.007). The idiopathic NF group also had a higher number of patients with ICU admissions and longer hospital stays than in the secondary NF group (52% vs. 13.6%, p = 0.012; 35.4 days vs. 23.95 days, p = 0.039). There were no significant differences in white blood cell counts (WBC), predisposing factors including comorbidity, and mortality rates. Multivariate analysis revealed that serum lactate levels and qSOFA score independently predicted the idiopathic streptococcal NF group (Odds ratio: 3.058, p = 0.031; Odds ratio: 2.306, p = 0.044). Conclusion: Patients presenting with idiopathic NF in the absence of skin lesions or traumatic history require close surveillance particularly in the presence of high CRP and serum lactate levels, even in the young and healthy population. Elucidating differences in clinical presentation will allow for refinement of the early clinical approach and optimize the outcomes.

背景：壞死性筋膜炎是一種罕見但致命的軟組織感染急症。早期診斷和及時治療對良好的有助於良好的預後。然而，特異性壞死性筋膜炎因無感染途徑的相關病史或外在傷口，缺乏明確的病因，致使早期診斷的困難，在臨床治療上亦將面臨更大的挑戰。目的及目標：將病患族群以不同的感染病因，分為特異性及次發性壞死性筋膜炎兩組。透過研究分析，試圖統計各組是否在臨床特徵，疾病表現及預後有差異。材料及方法：本研究為一回溯性研究，收錄自2013至2019期間，於單一醫療機構所有鏈球菌引發之壞死性筋膜炎患者。回顧病歷紀錄，收納了相關感染途徑、患者年齡、性別、慢性病史、微生物學、血液學、疾病嚴重度、手術次數、症狀出現至手術期間以及預後指標，以統計方式分析其臨床特徵，並比較兩組預後差異及疾病嚴重度。結果：在49位鏈球菌引起之壞死性筋膜炎病患中，有2例因缺乏足夠診斷壞死性筋膜炎的證據而被排除。其中，特異性壞死性筋膜炎發生在25位病患，而次發性則有22位。特異性壞死性筋膜炎組中，年輕族群（<50歲）比例較高，入院時疾病嚴重度較高（qSOFA評分較高）（0.84 vs 0.32,p=0.031）。特發性組患者的生化檢查中，CRP和Lactate也顯著升高（25.99 mg/dL vs 19.59 mg/dL，p=0.046；3.5 mg/dL vs 1.58 mg/dL, p=0.007）。即使兩組的死亡率無顯著差異，特異性組需要入住ICU的病患數量較多，住院時間較長（52% vs 13.6%，p=0.012；35.4天vs 23.95天，p=0.039）。多變量分析顯示，Lactate和qSOFA評分可以獨立預測特異性壞死性筋膜炎組（odds ratio,3.058，p=0.031；odds ratio,2.306，p=0.044）。結論：特異性鏈球菌壞死性筋膜炎由於缺乏明顯的病史及外傷，並能感染年輕和健康的族群，在早期診斷和及時治療方面為臨床一大挑戰。此類患者發炎指數異常升高，且疾病嚴重度較高的患者，在住院天數及需加護病房治療的比例也相對較高。透過本研究闡明臨床表現的差異，將有助於改善臨床診斷並及時提供有效的治療，以增進良好的預後。