What is the diagnosis and treatment for a 41-year-old female with left rib cage pain when lying down and switching positions, and left chest/breast pain when bending forward?

Diagnosis and Management of Positional Left-Sided Chest and Rib Pain in a 41-Year-Old Woman

The most likely diagnosis is musculoskeletal chest wall pain, specifically slipping rib syndrome or costochondritis, given the characteristic positional nature of symptoms; however, acute pericarditis must be ruled out first due to the positional worsening when lying down, and cardiac causes cannot be excluded without proper evaluation in a woman of this age. 1

Immediate Life-Threatening Conditions to Exclude First

Before attributing symptoms to musculoskeletal causes, you must systematically rule out cardiac and other emergent conditions:

Cardiac Evaluation

• Obtain a 12-lead ECG within 10 minutes to identify ST-segment elevation, PR depression (suggesting pericarditis), or signs of myocardial infarction, as women are at high risk for underdiagnosis of acute coronary syndrome despite atypical presentations 2, 3
• Measure cardiac troponin immediately upon presentation, as ACS can present atypically in women with positional or sharp pain 2, 3
• Sharp chest pain that worsens with lying supine and improves when leaning forward is pathognomonic for acute pericarditis, which requires urgent recognition 1, 2
• Women commonly present with atypical cardiac symptoms including sharp pain, positional changes, and accompanying dyspnea rather than classic substernal pressure 3

Other Emergent Causes

• Assess for pulmonary embolism if there is acute dyspnea, tachycardia, or pleuritic component to the pain 1
• Evaluate for aortic dissection red flags such as sudden "ripping" pain radiating to the back, though less likely given the chronic positional nature 1

Most Likely Diagnosis: Musculoskeletal Chest Wall Pain

Slipping Rib Syndrome

This is the leading musculoskeletal diagnosis given the specific positional triggers (lying down, switching positions, bending forward). 4, 5

Clinical Features

• Caused by hypermobility of the false ribs (8th-10th ribs) that slip or click, impinging the intercostal nerve 6
• Pain is sharp, located in lower chest and subcostal region, waxing and waning, and aggravated by specific movements or positions 4, 6
• Patients typically report months to years of symptoms before diagnosis 6

Diagnostic Approach

• Perform the hooking maneuver: Hook fingers under the lower costal margin and pull anteriorly to reproduce pain and potentially feel/hear a click 4, 5, 7
• Dynamic ultrasound can confirm slipping of the lowest rib over the adjacent rib if clinical diagnosis is uncertain 4, 6
• Standard imaging (CT, MRI, X-rays) is typically normal and unnecessary 4, 7

Costochondritis

• Characterized by localized tenderness at costochondral junctions with reproducible pain on palpation 2
• Pain worsens with specific movements and chest wall palpation 7
• Diagnosis is clinical based on point tenderness 7

Treatment Algorithm

Initial Conservative Management

• Reassurance that this is not a cardiac condition once life-threatening causes are excluded 4, 7
• Avoid postures and movements that worsen pain (lying flat, bending forward, twisting) 4, 7
• NSAIDs for pain control and anti-inflammatory effect 7
• Manual therapy and specific exercises may provide relief for musculoskeletal causes 7

Refractory Cases

• Intercostal nerve block for persistent symptoms despite conservative measures 4, 7, 6
• Surgical resection of slipping rib cartilages is the definitive treatment for slipping rib syndrome with good pain relief outcomes 6
• Rib stabilization is an emerging option for recurrent symptoms after initial surgery 6

Critical Pitfalls to Avoid

• Do not assume symptoms are noncardiac based on "atypical" presentation in a 41-year-old woman, as women frequently present with sharp or positional cardiac pain 3, 2
• Do not use nitroglycerin response as a diagnostic criterion, as esophageal spasm and other non-cardiac conditions also respond 1, 2
• Do not order excessive imaging (CT, MRI) for musculoskeletal chest pain once cardiac causes are excluded, as these are typically normal and the diagnosis is clinical 4, 7
• Do not delay cardiac workup if any high-risk features develop, such as symptoms interrupting normal activity, diaphoresis, nausea, lightheadedness, or syncope 1

Specific Examination Findings to Document

• Point tenderness along the costal margin or costochondral junctions 2, 7
• Positive hooking maneuver reproducing the patient's pain 4, 5
• Pain reproducible with specific chest wall palpation or movements 2, 7
• Absence of fever, friction rub, or signs of systemic illness that would suggest pericarditis or other inflammatory conditions 2