[Shoulder pain in inflammatory rheumatic diseases : Importance of musculoskeletal ultrasound].

Shoulder pain is a frequent reason for presentation in medical practices; however, it can sometimes be challenging to differentiate between an inflammatory versus mechanical or degenerative cause of shoulder pain. A swelling of the shoulder joint is only palpable in cases of pronounced clinical findings. In rheumatoid arthritis (RA) and psoriatic arthritis (PsA) the shoulder joints can be involved, which is early and frequent, particularly in the case of RA and is associated with a more severe course of the disease. Polymyalgia rheumatica (PMR) is typically manifested with shoulder and hip girdle pain. In all three diseases inflammatory changes, such as effusion/synovitis in the glenohumeral joint and subdeltoid bursitis are present in the sonographic examination. Specific ultrasound findings, such as peritendinitis and, in particular, bilateral involvement of the shoulder joints (inflammation of the long biceps tendon as well as the supraspinatus or subscapularis tendons) are associated with a definitive PMR. In addition, crystal arthropathies, such as calcium pyrophosphate deposition (CPPD) disease and gout should be included in the differential diagnostic considerations with respect to rheumatological diseases.