[Analysis of ultrasound as an adjunctive diagnostic tool for eosinophilic fasciitis].

<b>Objective:</b> This study investigates the utility of ultrasound in diagnosing eosinophilic fasciitis (EF). <b>Methods:</b> A retrospective analysis was conducted on the clinical and ultrasound data of 109 EF patients seen at the center between January 1, 2006, and March 31, 2024. The diagnostic efficacy of ultrasound for EF was evaluated by comparing forearm fascia ultrasound findings among EF patients, systemic sclerosis (SSc) patients, and healthy controls (HC). <b>Results:</b> Among the 109 EF patients (male-to-female ratio 2.2︰1), the median age of onset was 36 (29, 48) years, with a median disease duration of 7 (3, 12) months. The study also included 20 SSc patients [median age 49 (35, 61) years] and 20 HC individuals [median age 48 (29, 54) years]. Ultrasound assessments of forearm fascia in EF patients revealed a median fascial thickness of 1.9 (1.4, 2.4) mm. The median fascial thickness was 0.8 (0.7, 0.9) mm in SSc patients and 0.7 (0.5, 0.9) mm in HC individuals. Fascial thickness in EF patients was greater than in SSc (<i>Z</i>=-11.16,<i>P</i><0.001) and HC groups (<i>Z</i>=-11.87, <i>P</i><0.001). There was a correlation between fascia thickness and C-reactive protein (<i>r</i>=0.148, <i>P</i>=0.004), erythrocyte sedimentation rate (<i>r</i>=0.143, <i>P</i>=0.005), and immunoglobulin G (<i>r</i>=0.120, <i>P</i>=0.020) in EF patients. Receiver operating characteristic (ROC) curve analysis demonstrated a sensitivity of 84.0% and specificity of 95.9% for EF diagnosis, with an area under the curve (AUC) of 0.921 and a cut-off value of 1.005 mm. <b>Conclusion:</b> Ultrasound detection of forearm fascial thickening (>1 mm) aids in diagnosing eosinophilic fasciitis, indicating that ultrasound is a supplementary diagnostic tool for EF.