What could be causing persistent chest tightness in a patient using an inhaled corticosteroid, with normal spirometry, taking naproxen (non‑steroidal anti‑inflammatory drug), clear lung sounds, and oxygen saturation of 96% despite no apparent illness?

Persistent Chest Tightness with Normal Spirometry: Likely Non-Asthmatic Etiology

This presentation strongly suggests a non-pulmonary cause of chest tightness, and you should broaden your differential beyond asthma—particularly considering NSAID-related complications, gastroesophageal reflux disease (GERD), musculoskeletal pain, or cardiac causes.

Why This Isn't Typical Asthma

The clinical picture argues against poorly controlled asthma:

• Normal spirometry is common in well-controlled or mild asthma 1, but persistent symptoms despite inhaled corticosteroids with normal lung function and clear auscultation suggest the chest tightness has a different origin
• While FEV1 and symptoms correlate weakly in asthma 1, the complete absence of objective findings (normal spirometry, clear lungs, normal oxygen saturation) makes asthma an unlikely primary driver

Critical Consideration: Naproxen's Role

The naproxen use is particularly concerning and may be directly contributing to symptoms:

NSAID-Induced Bronchospasm Risk

• Naproxen can trigger severe bronchospasm in aspirin-sensitive patients, which can be fatal 2
• Cross-reactivity between aspirin and NSAIDs like naproxen is well-documented 2
• However, this typically presents with wheezing and objective airway obstruction—not seen here

NSAID-Related Gastrointestinal Effects

• Naproxen commonly causes GI discomfort and can produce chest pain mimicking cardiac or pulmonary symptoms 2
• Patients should be alert for epigastric pain and dyspepsia 2
• This is a more likely explanation given the clear lung examination

Recommended Diagnostic Approach

Immediate Actions:

1. Discontinue naproxen temporarily to assess if symptoms resolve—this is both diagnostic and therapeutic given the drug's potential to cause chest discomfort 2

2. Evaluate for GERD: NSAID use exacerbates reflux, which commonly presents as chest tightness without respiratory findings

3. Assess for musculoskeletal causes: Costochondritis or chest wall pain, potentially worsened by the underlying condition requiring naproxen

4. Rule out cardiac causes: Even with normal oxygen saturation, consider EKG and cardiac biomarkers, especially given NSAIDs increase cardiovascular risk 2

If Asthma Remains Suspected:

• Consider adding a long-acting beta-agonist (LABA) to the inhaled corticosteroid rather than increasing steroid dose alone—both options should be given equal weight 3
• LABAs are the preferred adjunctive therapy for patients ≥12 years with inadequate control on inhaled corticosteroids alone 3
• Never use LABAs as monotherapy 3

Testing for Asthma Variability:

Since spirometry can be normal in mild or well-controlled asthma 1:

• Perform bronchodilator challenge (improvement ≥12% and 200 mL in FEV1 confirms reversible obstruction) 1
• Consider peak flow monitoring at home to detect variability 1
• Methacholine challenge if diagnosis remains uncertain

Common Pitfalls to Avoid

• Don't intensify asthma therapy without confirming the diagnosis—normal spirometry with clear lungs and good oxygenation should prompt investigation of alternative causes
• Don't overlook medication side effects—the naproxen is a red flag that must be addressed 2
• Don't assume chest tightness equals asthma—this symptom has multiple etiologies, and the objective findings don't support active airway disease

Key Warning Signs

If the patient develops any of the following, urgent evaluation is needed:

• Chest pain with exertion, shortness of breath, or weakness (cardiac concerns with NSAID use) 2
• Melena, hematemesis, or severe epigastric pain (GI bleeding from naproxen) 2
• Actual wheezing or decreased oxygen saturation (true bronchospasm) 2