Grassi W, De Angelis R
Clinica Reumatologica, Università Politecnica delle Marche, Ancona, Italy.
Reumatismo. 2012 Jan 19;63(4):238-45. doi: 10.4081/reumatismo.2011.238.
Gout is a metabolic disease characterized by hyperuricemia and the deposition of monosodium urate (MSU) crystals in the joints and soft tissues, consisting of a self-limited acute phase characterized by recurrent attacks of synovitis and a chronic phase in which inflammatory and structural changes of the joints and periarticular tissues may lead to persistent symptoms. Acute gout is characterized by a sudden monoarthritis of rapid onset, with intense pain, mostly affecting the big toe (50% of initial attacks), the foot, ankle, midtarsal, knee, wrist, finger, and elbow. Acute flares also occur in periarticular structures, including bursae and tendons. The presence of characteristic MSU crystals in the joint fluid, appearing needle-like and showing strong negative birefringence by polarized microscopy, is pivotal to confirm the diagnosis of gout. The time interval separating the first attack from subsequent episodes of acute synovitis may be widely variable, ranging from a few days to several years. During the period between acute attacks the patient is asymptomatic even if MSU deposition may continue to increase silently. The factors that control the rate, location, and degree of ongoing deposition in gouty patients are not well defined. Chronic gout is the natural evolution of untreated hyperuricemia in patients with gouty attacks followed by pain-free intercritical periods. It is characterized by the deposition of solid MSU crystal aggregates in a variety of tissues including joints, bursae and tendons. Tophi can occur in a variety of locations including the helix of the ear, olecranon bursa, and over the interphalangeal joints. Their development is usually related with both the degree and the duration of hyperuricemia. About 20% of patients with gout have urinary tract stones and can develop an interstitial urate nephropathy. There is a strong association between hyperuricaemia and the metabolic syndrome (the constellation of insulin resistance, hypertension, obesity and dyslipidaemia), and gouty patients often have a medical history of kidney disease, diabetes mellitus and signs of vascular illness such as coronary artery disease, heart failure and stroke, resulting with a poor overall quality of life.
痛风是一种代谢性疾病，其特征为高尿酸血症以及单钠尿酸盐（MSU）晶体在关节和软组织中的沉积，包括以滑膜炎反复发作的自限性急性期和关节及关节周围组织的炎症和结构变化可能导致持续症状的慢性期。急性痛风的特征是突然发作的快速单关节炎，伴有剧烈疼痛，主要影响大脚趾（初始发作的50%）、足部、脚踝、跗中部、膝盖、手腕、手指和肘部。急性发作也发生在关节周围结构，包括滑囊和肌腱。关节液中存在特征性的MSU晶体，呈针状，在偏振显微镜下显示强烈的负双折射，对于确诊痛风至关重要。首次发作与随后急性滑膜炎发作之间的时间间隔可能差异很大，从几天到几年不等。在急性发作期间，即使MSU沉积可能继续无声增加，患者也无症状。控制痛风患者中持续沉积的速率、位置和程度的因素尚不明确。慢性痛风是痛风发作后无痛间歇期的未治疗高尿酸血症的自然演变。其特征是固体MSU晶体聚集体沉积在包括关节、滑囊和肌腱在内的各种组织中。痛风石可出现在包括耳轮、鹰嘴滑囊和指间关节等多种部位。它们的形成通常与高尿酸血症的程度和持续时间有关。约20%的痛风患者有尿路结石，并可发展为间质性尿酸盐肾病。高尿酸血症与代谢综合征（胰岛素抵抗、高血压、肥胖和血脂异常的组合）之间存在密切关联，痛风患者常有肾脏疾病、糖尿病病史以及血管疾病迹象，如冠状动脉疾病、心力衰竭和中风，导致总体生活质量较差。
