Ultrasound Features of the First Gout Attack and the Association with Duration of Hyperuricemia

Background: Gout is the most common form of inflammatory arthritis. Unfortunately, the burden of gout is increasing and treatment is still suboptimal. Nowadays, ultrasound is increasingly used to evaluate gout, especially in the early stage. However, little is known about the prevalence of the ultrasound signs in the first gout attack. Objectives: The aim of this study was to evaluate the prevalence of ultrasound features in the first gout attack and to correlate those features with the duration of hyperuricemia. Patients and Methods: We analyzed the ultrasound features of the knees, ankles and the first metatarsal-phalangeal joints (1st MTP) of patients with first gout attack compared to individuals with asymptomatic hyperuricemia (AHU). The findings were also compared with clinical, laboratory parameters and hyperuricemia duration. Results: Forty-eight patients with first gout attack gout were studied. The first attack affected the first MTP in 61%, the ankle in 33%, and the knee in 6% of the instances. The prevalence of snow-storm sign, double contour (DC) sign, tophi, bone erosion and abnormal blood flow was 92%, 29%, 6%, 13% and 83%, respectively. The prevalence of snow-storm sign and abnormal blood flow was significantly higher in the first attack of gout compared to AHU (P < 0.001). The hyperuricemia duration of patients with tophi and bone erosion was significantly longer than those with snow-storm sign and DC sign (7.5y and 6.5y vs 4.0y and 2y) (P = 0.004). Conclusion: Ultrasound features are associated with hyperuricemia duration. Furthermore, tophi and bone erosion can be detected in first gout attack. These data suggest that low-grade inflammation induced by uric acid may also occur in individuals with AHU.