Benefit of ultrasound in the phenotype recognition of psoriatic arthritis

To explore the difference in phenotype recognition of PsA patients in two clinical scenarios, physical examination with and without ultrasound assessment. PsA patients who visited the rheumatology and clinical immunology department of Peking University First Hospital between January 2010 and October 2020, with complete data of clinical and ultrasound assessment were enrolled. The phenotypes were first identified based on physical examination only, and then combined with enthesitis and dactylitis shown on power doppler and gray-scale ultrasound. The phenotype groupings without and with ultrasound assessment were presented with Wayne diagram. The distributions of different clinical phenotypes were compared by using test or Fisher's exact test. The differences of clinical phenotypes with and without ultrasound assessment were compared by using Wilcoxon signed rank test. A total of 227 patients with PsA were enrolled with one or more clinical domains. Physical examination revealed that psoriasis was in 209 (92.1%