Gout is a metabolic disorder caused by abnormalities in purine metabolism and/or impaired uric acid excretion. It is characterized by the deposition of monosodium urate crystals in joints or connective tissues, leading to recurrent episodes of acute arthritis. Gout can be categorized into two major types based on its etiology: primary and secondary. The majority of gout cases are associated with impaired uric acid excretion. The natural course of gout can be divided into three stages: (1) asymptomatic phase; (2) acute arthritis phase and intercritical phase; (3) chronic gouty arthritis and tophaceous phase. Acute gouty arthritis typically presents with sudden, severe joint pain, accompanied by redness, swelling, warmth, and tenderness of the affected joint and surrounding soft tissues. When large joints are involved, joint effusion may occur. Acute gouty arthritis often develops at night or in the early morning, is self-limiting, and usually resolves within two weeks. The most common site of acute gout flare-ups is the first metatarsophalangeal joint, followed by the midfoot, ankle, knee, wrist, fingers, and elbow joints. Acute gout attacks rarely affect the axial joints. Pain in these affected areas is often accompanied by limited function, significantly impacting a patient' s daily activities and quality of life. Uncommon sites of gout involvement, as well as gout with normal serum uric acid levels, can easily lead to misdiagnosis. Therefore, a comprehensive diagnosis requires a detailed medical history, physical examination, laboratory tests, and imaging studies. This case report describes a 19-year-old male who was admitted with recurrent anterior chest pain. The diagnosis at another hospital suggested ankylosing spondylitis. Physical examination revealed significant tenderness, redness, and swelling of the bilateral sternoclavicular joints, with local warmth and mildly restricted movement. MRI of the sacroiliac joints showed no significant abnormalities, and serum uric acid levels were normal. Chest dual-energy CT scans revealed multiple tophi in the sternum, bilateral clavicles, scapulae, multiple ribs, and along the edges of the sternum. Based on the patient' s medical history, physical findings, and imaging studies, a diagnosis of gout was confirmed. Treatment included urate-lowering therapy, pain management, and dietary adjustments. During a two-year follow-up period, the patient did not experience recurrent anterior chest pain, and multiple serum uric acid tests consistently showed levels below 300 μmol/L. Repeat chest dual-energy CT scans indicated significant reduction of tophi in the sternoclavicular joints and other affected areas.
痛风是嘌呤代谢异常和/或尿酸排泄障碍所致的代谢性疾病，以单钠尿酸盐结晶沉积于关节或软组织引发的复发性急性关节炎为特征，根据病因可分为原发性和继发性。多数病例与尿酸排泄障碍相关，其自然病程包括无症状期、急性关节炎期与间歇期、痛风石及慢性关节炎期。急性痛风性关节炎常表现为突发性关节剧痛，伴受累关节及周围软组织红肿、发热、压痛，大关节受累时可出现关节积液，发作常于夜间或清晨，具有自限性，多在两周内自行缓解。急性痛风发作最常见的部位是第一跖趾关节，其次为中足、踝、膝、腕、指和肘关节，极少累及中轴关节。疼痛常伴有活动受限，严重影响患者的日常生活与生活质量。若累及罕见部位或血尿酸正常时易致误诊，因此需结合病史、查体、实验室及影像学检查综合判断。本例为19岁男性，因反复前胸痛入院，外院曾疑诊强直性脊柱炎。查体可见双侧胸锁关节压痛、红肿，皮温增高伴活动受限。骶髂关节MRI无异常，血清尿酸正常。胸部双能量CT显示胸骨、双侧锁骨、肩胛骨、多根肋骨及胸骨边缘多处痛风石。依据患者病史、体征及影像学检查确诊为痛风，给予降尿酸、镇痛及饮食调整治疗。随访两年，患者胸痛未再发作，多次血尿酸检查均低于300 μmol/L，复查双能量CT显示胸锁关节等处的痛风石明显减少。
Keywords: Dual-energy computed tomography; Gout; Sternoclavicular joint; Tophus.