What is the differential diagnosis for a patient presenting with tingling and burning pain on the skin over the chest and stabbing pain inside the chest, without any other symptoms?

Differential Diagnosis: Tingling Burning Skin Pain + Stabbing Internal Chest Pain

The combination of tingling, burning pain on the chest skin with stabbing pain inside the chest most strongly suggests herpes zoster (shingles), especially if the pain follows a dermatomal distribution, though life-threatening cardiac and pulmonary causes must be excluded first. 1, 2

Immediate Life-Threatening Causes to Exclude

Before considering benign diagnoses, you must rule out conditions that can kill the patient:

• Acute Coronary Syndrome (ACS): While stabbing pain is atypical for ACS, patients with diabetes, women, and elderly patients may present with atypical symptoms including stabbing or sharp pain 1. Obtain an ECG within 10 minutes and measure cardiac troponin immediately 1. ACS typically presents with retrosternal pressure building over minutes, but can occur at rest without exertion 1, 2.

• Pulmonary Embolism: Presents with acute dyspnea, tachycardia (>90% of patients), and pleuritic chest pain 1, 2. The stabbing quality could represent pleuritic pain 3.

• Aortic Dissection: Characterized by sudden-onset "ripping" or "tearing" pain radiating to the back, with pulse differentials between extremities 1, 2. Less likely given the skin symptoms, but check for pulse differentials and blood pressure differences between arms 1.

• Pneumothorax: Presents with dyspnea, pain on inspiration, and unilateral absence of breath sounds 1, 2. Examine for decreased breath sounds unilaterally 1.

Most Likely Diagnosis: Herpes Zoster

Herpes zoster is the leading diagnosis when tingling, burning skin pain precedes or accompanies stabbing chest pain:

• Classic presentation: Pain in a dermatomal distribution that is triggered by touch, with characteristic unilateral rash following the dermatome 1. The rash may not appear until 2-5 days after pain onset 1.

• Pain characteristics: Burning, tingling, or stabbing quality affecting the skin surface, strictly unilateral, does not cross the midline 1.

• Physical examination: Look for vesicular rash in dermatomal distribution, hyperesthesia or allodynia (pain with light touch) over affected dermatome 1.

Other Musculoskeletal Causes

If herpes zoster is excluded and cardiac causes ruled out:

• Costochondritis/Tietze Syndrome: Tenderness of costochondral joints on palpation, pain reproducible with chest wall pressure 1, 2, 4. However, this typically does not cause burning skin pain 4, 5.

• Intercostal neuralgia: Can cause burning, stabbing pain along rib distribution, but usually follows trauma or has identifiable cause 5, 6.

• Chest wall muscle strain: Pain affected by palpation, breathing, turning, twisting, or bending 2, 5. Does not typically cause skin burning 5.

Critical Diagnostic Algorithm

Step 1: Obtain ECG within 10 minutes of presentation 1, 2. If ST-elevation or new ischemic changes present, treat as STEMI immediately 1.

Step 2: Perform focused cardiovascular examination checking for tachycardia, hypotension, pulse differentials, decreased breath sounds, or friction rub 1, 2.

Step 3: Measure cardiac troponin as soon as possible if any concern for ACS exists 1, 2.

Step 4: Examine skin carefully for vesicular rash in dermatomal distribution, check for hyperesthesia or allodynia 1.

Step 5: If initial ECG nondiagnostic but clinical suspicion for ACS remains high, perform serial ECGs at 15-30 minute intervals 1.

Step 6: Obtain chest radiograph to evaluate for pneumothorax, pneumonia, or widened mediastinum 1, 2.

Common Pitfalls to Avoid

• Do not dismiss atypical chest pain presentations: Stabbing or sharp pain can still represent ACS, particularly in women, elderly patients, and those with diabetes 1.

• Do not use nitroglycerin response as a diagnostic criterion: Esophageal spasm and other conditions also respond to nitroglycerin 2, 7, 8.

• Do not assume normal examination excludes ACS: Physical examination may be completely normal in uncomplicated ACS cases 1.

• Do not delay transfer for troponin testing: If ACS is suspected in an office setting, transfer urgently to the emergency department by EMS rather than waiting for office-based testing 1, 2.

High-Risk Features Requiring Immediate Emergency Department Transfer

Transfer immediately by EMS (not personal automobile) if any of the following are present 1, 2:

• Age >75 years with accompanying dyspnea, syncope, or acute delirium 2
• Any ECG abnormalities suggestive of ischemia 1, 2
• Hemodynamic instability (hypotension, tachycardia) 2
• Associated diaphoresis, dyspnea, nausea, or syncope 1, 2
• Diabetes, renal insufficiency, or known cardiovascular disease 1, 2