Adding ultrasound to clinical examination reduced frequency of enthesitis in primary care psoriasis patients with musculoskeletal complaints

OBJECTIVES: Part of the psoriasis patients with musculoskeletal complaints will have inflammation of the entheses. Entheseal inflammation is difficult to assess by clinical examination only. Therefore, we aimed to determine the frequency of clinically relevant ultrasound inflammation at the most commonly assessed entheses (MASEI; Madrid Sonographic Enthesis Index) in primary care psoriasis patients with one or more tender entheses.

METHODS: Adult primary care psoriasis patients with musculoskeletal complaints (tender enthesis or arthritis at physical examination) had an ultrasound examination of seven entheses according to the MASEI. Clinically relevant ultrasound inflammation was defined as active inflammation on ultrasound in combination with at least one clinical feature at the same enthesis. Active ultrasound inflammation contained positive power Doppler signal or in case of the plantar aponeurosis increased thickness. Structural changes entailed calcifications, enthesophytes, increased thickness, hypoechogeneicity indicating irregular fibre structure and erosions. Clinically, an enthesis was scored positive by a tender enthesis at clinical examination, reported pain in the history or self-reported pain in the questionnaires.

RESULTS: Of 542 primary care psoriasis patient, 111 patients had tender entheses and/or arthritis. These patients were both clinically and ultrasonographically evaluated. Active ultrasound inflammation accompanied with pain or tenderness at the enthesis was found in 36% of the patients (n=40). Most common were inflammation at the knee (n=11) and at the plantar aponeurosis (n=10). Structural changes were observed in 95% of the psoriasis patients independent of their clinical manifestation.

CONCLUSIONS: We found concurrent presence of ultrasound inflammatory changes and clinical symptoms in 36% of the primary care psoriasis patients who had tenderness at one or more entheseal sites.