Differential Diagnoses for New Onset Shoulder Pain Without Injury

Primary Differential Diagnoses

For patients over 35-40 years presenting with atraumatic shoulder pain, rotator cuff disease and degenerative changes are the predominant causes, while cervical radiculopathy must be ruled out if pain radiates down the arm with neurological symptoms 1, 2
Rotator cuff tendinopathy or tear is characterized by anterior shoulder pain worsened by overhead activities, weakness with abduction and external rotation 2, 3
Anterior shoulder pain is often associated with rotator cuff or biceps tendon pathology 1, 2
Superior shoulder pain is commonly related to acromioclavicular joint disease 2
Scapular region pain can be referred pain from cervical spine or rotator cuff 2

The American College of Radiology recommends obtaining standard shoulder radiographs (3 views minimum) as the mandatory first step for ALL patients with new shoulder pain, regardless of suspected etiology 6, 4, 3
Required radiographic views include AP views in internal and external rotation 3, and axillary or scapula-Y view 6, 4
Radiographs effectively demonstrate fractures, dislocations, arthritis, AC joint pathology, and calcific tendinitis 6, 3

The American College of Radiology suggests that most soft-tissue shoulder injuries can undergo conservative management before considering surgery 7, 5
Acetaminophen is recommended as the first-line pain management option, with a maximum daily dose of 4 grams 3
Topical agents, such as methyl salicylate, capsaicin cream, or menthol, can be used as a second-line option for mild-moderate pain 3
Intra-articular glucocorticoid injections can be beneficial for pain not adequately relieved by systemic medications, especially with evidence of inflammation 3
Physical therapy protocol should include range of motion exercises, scapular stabilization exercises, and electrical stimulation to improve shoulder lateral rotation 1, 3, 2

Immediate referral is indicated for suspected septic arthritis, neurological deficits, unstable or significantly displaced fractures, shoulder joint instability with recurrent dislocations, and suspected massive rotator cuff tears in younger active patients 3, 2, 7, 2
The American College of Radiology recommends elective orthopedic referral for failure of 6-12 weeks of appropriate conservative treatment or progressive functional decline despite therapy 2