What are the possible causes and treatments for left-sided pain that worsens with breathing?

Left-Sided Pleuritic Chest Pain: Diagnostic Approach and Management

Left-sided chest pain that worsens with breathing requires immediate evaluation to exclude life-threatening conditions—specifically pulmonary embolism, pneumothorax, acute coronary syndrome, aortic dissection, and pericarditis—before considering benign etiologies. 1

Immediate Life-Threatening Causes to Exclude

Pulmonary Embolism

• Most common serious cause, found in 5-21% of patients presenting with pleuritic chest pain 2
• Presents with dyspnea, pleuritic pain, tachycardia (>90% of cases), and tachypnea 3, 1
• Use a validated clinical decision rule to guide D-dimer testing, ventilation-perfusion scanning, or CT angiography 2
• Pleural effusion develops in 46% of PE cases and can cause ongoing pleuritic discomfort 1

Pneumothorax

• Classic triad: dyspnea, pleuritic pain on inspiration, and unilateral absence of breath sounds 3, 1
• Hyperresonant percussion on the affected side 1
• Requires immediate chest radiography for confirmation 1

Acute Coronary Syndrome

• Critical pitfall: Pleuritic pain occurs in 13% of ACS patients 1
• Sharp chest pain that increases with inspiration makes ischemic heart disease less likely but does not exclude it 3, 1
• 7% of patients with reproducible chest wall tenderness still have ACS 1
• Obtain ECG within 10 minutes and cardiac troponin as soon as possible 3, 1

Aortic Dissection

• Sudden onset "ripping" chest pain radiating to the back 3
• Pulse differential in 30% of cases (Type A > Type B) 3
• Severe pain + abrupt onset + pulse differential + widened mediastinum on chest X-ray = >80% probability 3

Pericarditis

• Sharp, pleuritic pain that improves when sitting forward and worsens when supine 3, 1
• Friction rub on examination (biphasic sound) 3, 1
• ECG shows widespread ST-elevation with PR depression 1
• Fever may be present 3

Common Non-Life-Threatening Causes

Pneumonia

• Localized pleuritic pain with fever, productive cough 3, 1
• Regional dullness to percussion, egophony, possible friction rub 3, 1
• Chest radiography confirms diagnosis 1

Costochondritis/Tietze Syndrome

• Tenderness of costochondral joints on palpation 3, 1
• Warning: Do not assume reproducible chest wall tenderness excludes serious pathology—7% still have ACS 1

Viral Pleurisy

• Common causative agents include Coxsackieviruses, respiratory syncytial virus, influenza, parainfluenza, mumps, adenovirus, cytomegalovirus, and Epstein-Barr virus 2
• Diagnosis of exclusion after ruling out serious causes 2

Other Causes

• Herpes zoster: Pain in dermatomal distribution triggered by touch, with characteristic unilateral dermatomal rash 3, 1
• Myocarditis: Fever, chest pain, heart failure signs, S3 gallop 3, 1
• Pleural effusion: May cause ongoing pleuritic discomfort 1

Mandatory Initial Diagnostic Workup

Immediate Testing (Within 10 Minutes)

• ECG: Obtain within 10 minutes to identify STEMI, pericarditis patterns, or signs of PE 3, 1
• Serial ECGs if initial is nondiagnostic and clinical suspicion remains high 3

Essential Laboratory Testing

• Cardiac troponin: Measure as soon as possible in acute presentations to exclude myocardial injury 3, 1
• D-dimer: If PE is suspected based on validated clinical decision rule 2

Imaging

• Chest radiography: Essential to evaluate for pneumothorax, pneumonia, pleural effusion, or widened mediastinum 3, 1
• CT angiography: If PE remains in differential after initial workup 2

Physical Examination Priorities

• Vital signs: Tachycardia and tachypnea present in >90% of PE cases 1
• Breath sounds: Unilateral decreased or absent breath sounds suggest pneumothorax or large pleural effusion 3, 1
• Pleural friction rub: Biphasic sound indicating pleural inflammation 1
• Pulse differential: Check bilateral extremity pulses for aortic dissection 3
• Chest wall palpation: Assess for costochondral tenderness, but do not rely on this to exclude cardiac causes 1
• Positional changes: Assess if pain changes with position (worse supine suggests pericarditis) 3

Critical Management Pitfalls to Avoid

• Never use nitroglycerin response as a diagnostic criterion—relief does not confirm or exclude myocardial ischemia 3, 1
• Do not delay transfer for troponin testing in office settings—patients with suspected ACS should be transported urgently to ED by EMS 3, 1
• Do not assume reproducible chest wall tenderness excludes serious pathology—7% of patients with palpable tenderness have ACS 1
• Sharp, pleuritic pain does not exclude cardiac ischemia—it makes it less likely but does not rule it out 3, 1

Treatment Approach

For Life-Threatening Causes

• Activate emergency response system immediately if open chest wound or signs of tension pneumothorax 3
• Transport urgently to ED by EMS for suspected ACS, PE, aortic dissection, or pneumothorax 3
• Treat according to specific guidelines once diagnosis confirmed 3

For Benign Causes

• NSAIDs are appropriate for pain management in virally triggered or nonspecific pleuritic chest pain 2
• For pneumonia patients who smoke or are >50 years old, document radiographic resolution with repeat chest X-ray six weeks after initial treatment 2