血管性水肿

content: In hereditary angioedema, often no direct cause is identifiable, although mild trauma, including dental work and other stimuli, can cause attacks. There is usually no associated itch or urticaria, as it is not an allergic response. Patients with HAE can also have recurrent episodes (often called "attacks") of abdominal pain, usually accompanied by intense vomiting, weakness, and in some cases, watery diarrhea, and an unraised, nonitchy splotchy/swirly rash. These stomach attacks can last one to five days on average, and can require hospitalization for aggressive pain management and hydration. Abdominal attacks have also been known to cause a significant increase in the patient's white blood cell count, usually in the vicinity of 13,000 to 30,000. As the symptoms begin to diminish, the white count slowly begins to decrease, returning to normal when the attack subsides. As the symptoms and diagnostic tests are almost indistinguishable from an acute abdomen (e.g. perforated appendicitis) it is possible for undiagnosed HAE patients to undergo laparotomy (operations on the abdomen) or laparoscopy (keyhole surgery) that turns out to have been unnecessary.  The hereditary form (HAE) often goes undetected for a long time, as its symptoms resemble those of more common disorders, such as allergy or intestinal colic. An important clue is the failure of hereditary angioedema to respond to antihistamines or steroids, a characteristic that distinguishes it from allergic reactions. It is particularly difficult to diagnose HAE in patients whose episodes are confined to the gastrointestinal tract. Besides a family history of the disease, only a laboratory analysis can provide final confirmation. In this analysis, it is usually a reduced complement factor C4, rather than the C1-INH deficiency itself, that is detected. The former is used during the reaction cascade in the complement system of immune defense, which is permanently overactive due to the lack of regulation by C1-INH.  Angioedema is classified as either hereditary or acquired.
title: 获得性血管性水肿.
content: Acquired angioedema (AAE) can be immunologic, nonimmunologic, or idiopathic. It is usually caused by allergy and occurs together with other allergic symptoms and urticaria. It can also occur as a side effect to certain medications, particularly ACE inhibitors. It is characterized by repetitive episodes of swelling, frequently of the face, lips, tongue, limbs, and genitals. Edema of the gastrointestinal mucosa typically leads to severe abdominal pain; in the upper respiratory tract, it can be life-threatening.
title: 过敏.
content: In allergic angioedema, avoidance of the allergen and use of antihistamines may prevent future attacks. Cetirizine is a commonly prescribed antihistamine for angioedema. Some patients have reported success with the combination of a nightly low dose of cetirizine to moderate the frequency and severity of attacks, followed by a much higher dose when an attack does appear. Severe angioedema cases may require desensitization to the putative allergen, as mortality can occur. Chronic cases require steroid therapy, which generally leads to a good response. In cases where allergic attack is progressing towards airway obstruction, epinephrine may be life-saving.
title: 药物导致.
content: ACE inhibitors can induce angioedema. ACE inhibitors block the enzyme ACE so it can no longer degrade bradykinin; thus, bradykinin accumulates and causes angioedema. This complication appears more common in African-Americans. In people with ACE inhibitor angioedema, the drug needs to be discontinued and an alternative treatment needs to be found, such as an angiotensin II receptor blocker (ARB) which has a similar mechanism but does not affect bradykinin. However, this is controversial, as small studies have shown some patients with ACE inhibitor angioedema can develop it with ARBs, as well.  Future attacks of hereditary angioedema can be prevented by the use of androgens such as danazol, oxandrolone or methyltestosterone. These agents increase the level of aminopeptidase P, an enzyme that inactivates kinins; kinins (especially bradykinin) are responsible for the manifestations of angioedema. 活性减弱的雄性激素如达那唑、司坦唑(康力龙)、羟甲烯龙(康复龙)等治疗先天性C1INH缺陷,可纠正其生化缺损并有预防发作的效用,但不能用于小儿和孕妇。

Summary: 血管神经性水肿是真皮、皮下组织、黏膜的局部肿胀。可发生于面部、舌头、喉、腹部、四肢。常与荨麻疹相关,荨麻疹是皮肤的红肿。 Onset is typically over minutes to hours. 基本机制涉及组胺或缓激肽。 与组胺相关的是由于对过敏原的过敏反应,如蚊虫叮咬,食物,或药品。 与缓激肽相关的是遗传问题称作获得性C1酯酶抑制剂缺乏,药物有血管紧张素转换酶抑制剂, 或淋巴组织增生性疾病. 为保护呼吸道通畅,对呼吸道特别是喉部发作水肿,必要时应进行气管插管或环甲状软骨切开术。组胺相关血管神经性水肿可抗组织胺药:对症治疗常采用抗组胺受体H1拮抗剂,对顽固的、应用抗组胺受体拮抗剂无效的患者,可合并应用抗组胺受体H2拮抗剂如西咪替丁(甲氰咪呱)或兰替丁,有时可取得满意效果。酮体芬亦可合并使用。拟交感神经药物主要用于急性荨麻疹和(或)神经性水肿,尤其是喉水肿患者,应用0.1%肾上腺素皮下注射,对严重急性过敏性反应可隔20～30分钟注射。同时给予糖皮质类固醇激素静脉滴注,氨茶碱口服或静脉注射。 缓激肽相关的疾病可用C1酯酶抑制物, 艾卡拉肽, 艾替班特治疗。 Fresh frozen plasma may be used instead. In the United States the disease affects about 100,000 people a year.

Angioedema: Angioedema is an area of swelling of the lower layer of skin and tissue just under the skin or mucous membranes. The swelling may occur in the face, tongue, larynx, abdomen, or arms and legs. Often it is associated with hives, which are swelling within the upper skin. Onset is typically over minutes to hours. The underlying mechanism typically involves histamine or bradykinin. The version related to histamine is due to an allergic reaction to agents such as insect bites, foods, or medications. The version related to bradykinin may occur due to an inherited problem known as C1 esterase inhibitor deficiency, medications known as angiotensin-converting enzyme inhibitors, or a lymphoproliferative disorder. Efforts to protect the airway may include intubation or cricothyroidotomy. Histamine-related angioedema can be treated with antihistamines, corticosteroids, and epinephrine. In those with bradykinin-related disease a C1 esterase inhibitor, ecallantide, or icatibant may be used. Fresh frozen plasma may be used instead. In the United States the disease affects about 100,000 people a year.