High-frequency ultrasound characteristics and causes of misdiagnosis of early joint lesions in patients with psoriatic arthritis without skin lesions
ZHOU Jing
ZHAO Yuanying
MA Xueying
LAN Hailong
WANG Zhengxiang
QIN Lanying
Abstract：Objective To analyze the high-frequent ultrasonic characteristics of early joint lesions in patients with psoriatic arthritis(PsA)without skin lesions and the causes of misdiagnosis.Methods A retrospective analysis was conducted on the clinical data of 2 patients with PsA without skin lesions who were admitted from March 2023 to October 2024.Results Both of the two patients presented with knee joint pain,accompanied by pain in the joints of both hands.At the initial examination,no rashes were observed.The high-frequency ultrasound examination results showed one case of synovitis with effusion in both knee joints,and osteophyte formation in both knees,and one case of bilateral knee joint effusion,with the right side being more prominent,with thickening of the right knee synovium and a cyst inferolateral to the right popliteal fossa.Both patients were initially misdiagnosed as having arthritis and received corresponding treatments but without any improvement.In one patient,a red rash and scales appeared on the scalp,accompanied by itching;in the other patient,the fingernails of ten fingers showed varying degrees of thimble-like changes and longitudinal ridges,and a strip-like rash was observed at the 9-10 o'clock position around the umbilicus.No rashes were found in other areas.After relevant examinations,they were diagnosed with PsA.After adjusting the treatment,the joint pain of the patients was relieved,and the rash completely disappeared after 6 months.Conclusion In the early stage of PsA without skin lesion manifestations,there are no typical skin lesions.However,high-frequency ultrasound can reveal changes such as synovitis,joint effusion,thickening of the synovium,and popliteal cysts.The main reason for misdiagnosis is that patients have no obvious skin lesion symptoms.Clinicians should enhance their understanding of this disease and pay attention to skin and nail examinations for patients with unexplained joint pain.Combined with auxiliary methods such as high-frequency ultrasound,the rate of misdiagnosis can be reduced.
Keywords：psoriatic arthritismisdiagnosisarthritishigh-frequency ultrasoundMethotrexatedifferential diagnosis
Publication Date：2026-01-28
Online Publishing Date：2026-02-05(First online date of this platform, not the publication date of the document)
Pages：7( 14-20 )