What is the differential diagnosis and initial management approach for a patient presenting with reproducible chest tenderness?

Reproducible Chest Tenderness: Differential Diagnosis and Management

While reproducible chest wall tenderness substantially reduces the likelihood of acute coronary syndrome (ACS) with a negative predictive value of 98.1%, approximately 7% of patients with reproducible chest wall pain still have ACS, making ECG and cardiac troponin mandatory before safely ruling out cardiac causes. 1, 2

Immediate Mandatory Evaluation

Regardless of reproducible tenderness findings, the following must be obtained:

• Obtain a 12-lead ECG within 10 minutes of patient arrival to identify STEMI, new left bundle branch block, Q waves, or T wave inversions 3, 1
• Measure cardiac troponin as soon as possible after presentation in any patient with acute chest pain 3, 1
• Perform a focused cardiovascular examination to identify life-threatening causes including ACS, aortic dissection, pulmonary embolism, and esophageal rupture 3, 1

Critical pitfall: Never delay transfer to the emergency department for troponin testing in office settings—patients with suspected ACS should be transported urgently by EMS 3, 1, 4

Differential Diagnosis for Reproducible Chest Tenderness

Musculoskeletal Causes (Most Common with Reproducible Tenderness)

• Costochondritis/Tietze syndrome: Tenderness of costochondral joints on palpation, but remember that 7% of patients with reproducible chest wall pain still have ACS 3, 1, 2
• Chest wall pain: Localized pain reproducible by palpation, but this finding alone has low specificity (48.6%) for ruling in benign causes 5, 2

Cardiac Causes (Must Be Excluded Despite Reproducible Tenderness)

• Acute coronary syndrome: May present with reproducible tenderness in some cases; examination may be completely normal in uncomplicated AMI 3, 1
• Pericarditis: Sharp, pleuritic pain that worsens supine and improves sitting forward; look for friction rub and widespread ST elevation with PR depression on ECG 3, 1, 4
• Myocarditis: Fever, chest pain, heart failure signs, S3 gallop; can mimic musculoskeletal pain 3, 1

Pulmonary Causes

• Pneumonia: Localized pleuritic pain, fever, friction rub may be present, regional dullness to percussion, egophony 3, 1, 4
• Pneumothorax: Pleuritic pain on inspiration, unilateral absence of breath sounds, hyperresonant percussion 3, 1, 4
• Pulmonary embolism: Tachycardia and dyspnea in >90% of patients; pleuritic pain with inspiration 3, 1, 4

Other Serious Causes

• Herpes zoster: Pain in dermatomal distribution triggered by touch; characteristic unilateral dermatomal rash (may precede rash appearance) 3, 1, 4
• Aortic dissection: Sudden onset severe "ripping" chest or back pain with pulse differential in 30% of cases 3, 4
• Esophageal rupture: History of emesis, subcutaneous emphysema, pneumothorax in 20% of patients 3

Algorithmic Management Approach

Step 1: Immediate Risk Stratification

• If any clinical evidence of ACS or life-threatening cause: Activate 9-1-1 for EMS transport to ED 1, 4
• If stable with reproducible pain: Proceed to ECG within 10 minutes 1

Step 2: ECG Interpretation

• STEMI or new LBBB: Immediate EMS transport for reperfusion 1
• ST-T abnormalities suggesting ischemia: Urgent ED evaluation required 1
• Widespread ST elevation with PR depression: Consider pericarditis, obtain troponin and echocardiogram 1, 4
• Normal ECG: Proceed to troponin measurement 1

Step 3: Troponin Results

• Elevated troponin: Admit for ACS evaluation regardless of reproducible tenderness 1
• Normal troponin (single measurement): Consider serial troponins or high-sensitivity troponin protocol based on time from symptom onset 3

Step 4: Additional Diagnostic Testing Based on Clinical Suspicion

• Chest X-ray: For pneumonia, pneumothorax, pleural effusion, or widened mediastinum 1, 4, 6
• CT angiography: If aortic dissection or pulmonary embolism suspected 4, 6
• Echocardiography: If pericardial effusion, wall motion abnormalities, or valvular disease suspected 1, 4

Key Physical Examination Findings

• Reproducible chest wall tenderness: High negative predictive value (98.1%) but low specificity (48.6%) for ruling in benign causes 2
• Friction rub: Suggests pericarditis or pneumonia 3, 4
• Unilateral decreased breath sounds: Pneumothorax or large pleural effusion 3, 4
• Pulse differential: Aortic dissection (30% sensitivity) 3
• Tachycardia and tachypnea: Present in >90% of pulmonary embolism cases 3, 4

Critical Pitfalls to Avoid

• Never assume reproducible chest wall tenderness excludes serious pathology—7% of patients with palpable tenderness have ACS 1, 2
• Do not use nitroglycerin response as a diagnostic criterion—relief with nitroglycerin does not confirm or exclude myocardial ischemia 4
• Sharp, pleuritic pain does not exclude cardiac ischemia—ACS may present with pleuritic features in 13% of cases 4
• Avoid delaying transfer for troponin testing in office settings—transport suspected ACS patients urgently to ED by EMS 3, 1, 4