LAUSR

Background Dactylitis is a manifestation of gout that can occur on debut or throughout the course of the disease, although it is usually considered a sign of chronicity or a hallmark of long-term disease. Classically, the synovitis or tenosynovitis mediated by the deposit of microcrystals has been interpreted as an inflammatory effect due to proximity. The etiological prevalence based on imaging studies is unknown. Objectives To determine the prevalence of different ultrasonographic features of dactylitis of the hands in patients with gout. Methods A cross-sectional study was conducted based on a registry of ultrasound images of patients with gout and clinical dactylitis either in debut or throughout evolution. The selection of patients followed strictly clinical criteria based on the corresponding medical reports. All images were obtained in a medium-high gamma GE equipment and were obtained by the same operator over three years. Given that no comparisons were planned, no masking of the clinical situation of the patients was made in the eyes of the interpreter. The interpretation of findings was dichotomous in the determination of synovitis, tenosynovitis and enthesopathy according to EULAR definition criteria. The identification of tophi was made according to the definition of Avila Fernandes et al. (doi: 10.1007/s00256-010-1008-z) The overlapping of findings was counted independently at the moment of establishing the prevalence. Results We included images of 66 patients diagnosed with gout and with dactylitis of at least one finger at the time of the ultrasound evaluation. The mean age of the patients was 59.2 SD 4.3 years. Sixty-two patients were male. Of the total number of patients, 60 had tenosynovitis of the flexor tendinous apparatus (90.9%). Four of these patients also presented tenosynovitis of the tendinous extensor apparatus. No patient presented only extensor tenosynovitis. Enthesopathy was identified in 6 patients (9.1%), in no case did enthesopathy occur with power Doppler signal. Synovitis was identified in 43 patients (65.1%). Of these, in 13 patients a grade I was registered and in 26 a power Doppler signal was demonstrated. Tophi were identified in 16 patients (242%). Conclusions CONCLUSIONS: This is, as far as we know, the first iconographic study of gouty dactylitis based on ultrasound. According to our results, tenosynovitis of the flexors is the most frequent finding in gouty dactylitis while enthesopathy is rather rare. The presence of significant synovitis is the second most frequent finding while tophi as conditioning agents of synovitis were the least frequent finding. We understand that the knowledge of the echographic characteristics of gouty dactylitis can serve as a clinical guide when making therapeutic decisions in cases were this clinical sign lasts despite the control of other manifestations. Disclosure of Interest None declared