坏死性筋膜炎

title: 症状.
content: 坏死性筋膜炎多为急性发作,但也有少数以慢性型态出现。局部症状类似于一般组织感染,常因发病较轻且隐匿,得不到病人注意,使感染在24小时内波及整个全身。早期症状为皮肤红肿、发热、变硬,肿胀呈紫红色片状,边界不清,且伴有强烈疼痛感。病人可伴有流感症状,包括发热、寒颤、腹泻、呕吐、四肢无力、心动过速及肌肉酸痛。此时皮下组织已经坏死,因淋巴通路已被迅速破坏,故少有淋巴管炎和淋巴结炎。这一阶段一般持续数小时至数天。有些会被误诊为其他疾病如蜂窝组织炎。  当病灶部位的感觉神经被破坏后,则早期感染局部的剧烈疼痛可被麻木或麻痹所替代,疼痛缓解,患部出现麻木感。该病病情进入中期时,感染局部变得更加鲜红,皮肤颜色逐渐发紫、发黑,由于血管栓塞和营养血管被破坏而导致的含血性液体水泡和大疱逐渐增多,疼痛和肿胀加剧,全身症状变得严重。到了病情三期或终末期,表现变为持续高热,白细胞明显升高,全身有明显的毒血症,低血压、弥漫性血管内凝血、中毒性休克、反应迟钝或意识丧失、酸中毒和多器官衰竭(如肾)。血管硬阻的结果导致皮肤出现干性坏疽和表皮分离,出现四周绕以红晕的坏死黑色焦痂,类似于三度烧伤。当中毒症状逐渐加重时,多数病人终因败血症或休克而死亡。  坏死性筋膜炎的并发症有贫血、中毒性休克、多器官功能衰竭和弥漫性血管内凝血等。  该病易患因素有:糖尿病、肾病、肥胖、外周血管疾病、免疫低下、营养不良、年迈、静脉吸毒等。其他包括酗酒、吸烟、高血压、AIDS、肝肾功能异常、慢性阻塞性肺病、长期应用皮质类固醇激素、慢性皮肤溃疡等。此外,皮肤擦伤、烫伤、刺伤、动物或昆虫咬伤、皮下注射胰岛素或静脉吸毒、水痘等,均可诱发该病,手术如剖宫产、子宫切除术、小切口输卵管切除术、腹腔镜、不全流产常常是腹壁坏死性筋膜炎的诱因。
title: 发病机制.
content: 坏死性筋膜炎是需氧性和厌氧性细菌协同作用的结果。在全身或局部组织出现免疫损害后,多种细菌侵入皮下组织和筋膜,需氧菌先消耗组织中的氧气,使氧还电势降低,体系还原性增强。同时细菌分泌的酶将组织中的过氧化氢分解,创造出适宜厌氧菌生存繁殖的少氧环境。细菌感染沿着筋膜组织迅速广泛地潜行蔓延,引起感染组织广泛性地炎症充血、水肿,继而皮肤和皮下的小血管网发生炎性栓塞,组织营养障碍导致皮肤缺血性坑道样坏死甚至发生环行坏死。镜检可见血管壁有明显的炎性表现,真皮层深部和筋膜中有中性粒细胞浸润受累筋膜内血管有纤维性栓塞,动静脉壁出现纤维素性坏死,革兰染色可在破坏的筋膜和真皮中发现病原菌肌肉无损害的表现。
title: 治疗.
content: 坏死性筋膜炎的治疗关键是早期诊断和彻底手术清创,迅速切除坏死组织,同时对肿胀组织给予多次广泛切开达深筋膜并充分敞开引流,必要时进行多次扩创。创面用双氧水纱布湿敷,以阻止厌氧菌繁殖,同时联合应用大剂量敏感抗生素。其他治疗方法包括纠正休克及多器官损伤、抗凝剂、免疫球蛋白、高压氧、营养支持疗法、伤口修复以及择期行植皮术等。

Summary: 坏死性筋膜炎(英文:Necrotizing fasciitis)又称食肉菌感染或噬肉菌感染,是身体内软组织坏死导致的感染疾病,是会突然发病并且快速散播的严重疾病,症状包含在感染部位皮肤呈现红色或紫色、强烈的疼痛、高烧以及呕吐。其最普遍感染的部位在四肢跟会阴。 通常感染通过受损的皮肤(如割伤或烧伤)进入人体,其风险因子包括例如糖尿病、癌症、肥胖、酗酒、静脉药物注射以及周边动脉阻塞等引起的免疫功能低下。此疾病很少会在人群间传播,坏死性筋膜炎可依照所感染的病原体物种被分为四种类型。50%到88%的病例由一种以上的细菌感染造成,有将近三分之一的病例是耐甲氧西林金黄色葡萄球菌(MRSA)感染影像学检查有助于该疾病的确诊。 良好的伤口护理以及有效的洗手法可有助预防坏死性筋膜炎的发生,在治疗上,清创手术与抗生素静脉注射是常见的方法,抗生素治疗通常包括几种抗生素的组合使用,包括芐基青霉素(penicillin G)、克林霉素(clindamycin)、万古霉素(vancomycin)、庆大霉素(gentamicin)等。耽搁手术在一定程度上会导致更高的死亡风险,即使经过完善的治疗,坏死性筋膜炎的死亡率仍达25%至35%。 坏死性筋膜炎每年在十万人中就有0.4到1人罹患,男性与女性罹患几率相同。本疾病的患病几率会随年龄增长而增加,而孩童很少患病。坏死性筋膜炎早在迟至公元前四百年的希波克拉底时期即有描述,但Necrotizing fasciitis一词首次广泛使用是在公元1952年。

Necrotizing fasciitis: Necrotizing fasciitis (NF), also known as flesh-eating disease, is an infection that results in the death of parts of the body's soft tissue. It is a severe disease of sudden onset that spreads rapidly. Symptoms usually include red or purple skin in the affected area, severe pain, fever, and vomiting. The most commonly affected areas are the limbs and perineum. Typically, the infection enters the body through a break in the skin such as a cut or burn. Risk factors include poor immune function such as from diabetes or cancer, obesity, alcoholism, intravenous drug use, and peripheral artery disease. It is not typically spread between people. The disease is classified into four types, depending on the infecting organism. Between 55 and 80% of cases involve more than one type of bacteria. Methicillin-resistant "Staphylococcus aureus" (MRSA) is involved in up to a third of cases. Medical imaging is often helpful to confirm the diagnosis. Necrotizing fasciitis may be prevented with proper wound care and handwashing. It is usually treated with surgery to remove the infected tissue, and intravenous antibiotics. Often, a combination of antibiotics is used, such as penicillin G, clindamycin, vancomycin, and gentamicin. Delays in surgery are associated with a much higher risk of death. Despite high-quality treatment, the risk of death is between 25 and 35%. Necrotizing fasciitis occurs in about 0.4 people per 100,000 per year in the US, and about 1 per 100,000 in Western Europe. Both sexes are affected equally. It becomes more common among older people and is rare in children. It has been described at least since the time of Hippocrates. The term "necrotizing fasciitis" first came into use in 1952.