Differential Diagnosis for Shoulder Pain

The patient's symptoms of shoulder pain that worsens with overhead activities and improves with rest, along with a history of working as a house painter, suggest a range of potential diagnoses. Here is a categorized differential diagnosis:

• Single Most Likely Diagnosis

  • Rotator Cuff Tendinitis: This condition is common in individuals who perform repetitive overhead activities, such as house painters. The pain pattern described, worsening with overhead lifting and improving with rest, is consistent with rotator cuff tendinitis. The nocturnal aching is also typical, as the rotator cuff can become irritated and inflamed, leading to nighttime pain.

• Other Likely Diagnoses

  • Rotator Cuff Tear: Similar to tendinitis, tears in the rotator cuff can cause pain with overhead activities and at night. The mechanism of injury and occupation increase the likelihood of this condition.
  • Subacromial Bursitis: Inflammation of the subacromial bursa, which reduces friction between the rotator cuff and the acromion, can cause pain with overhead activities and may be related to the patient's occupation.
  • Adhesive Capsulitis (Frozen Shoulder): Although less likely given the specific exacerbating factors, frozen shoulder can cause shoulder pain and stiffness, particularly at night. However, the pain pattern and occupation suggest this is less likely than rotator cuff pathology.

• Do Not Miss Diagnoses

  • Thoracic Outlet Syndrome: While less common, thoracic outlet syndrome can cause shoulder and arm pain due to compression of the nerves and/or blood vessels that pass through the thoracic outlet. Missing this diagnosis could lead to prolonged discomfort and potential neurological or vascular complications.
  • Referred Pain from Cervical Spine: Cervical spine disorders, such as herniated discs or cervical spondylosis, can refer pain to the shoulder region. Failing to consider and diagnose cervical spine issues could lead to inadequate treatment and ongoing pain.
  • Bone Tumors or Metastases: Although rare, primary bone tumors or metastatic disease to the shoulder region could present with pain, especially at night. Missing these diagnoses could have severe consequences, including delayed treatment of a potentially curable condition.

• Rare Diagnoses

  • Polymyalgia Rheumatica: An inflammatory condition that can cause shoulder pain and stiffness, particularly in older adults. While it's a less common cause of shoulder pain, its presence can be suggested by systemic symptoms such as fever, weight loss, and proximal muscle weakness.
  • Infectious or Inflammatory Arthritis: Conditions like septic arthritis or rheumatoid arthritis can cause shoulder pain but are less likely given the occupation-related exacerbation and the lack of systemic symptoms described.