Overview
Definition
A specific form of chronic, progressive fibrosing interstitial pneumonia of unknown cause, occurring primarily in older adults, limited to the lungs.
Epidemiology
Poor prognosis with a median survival of 3-5 years after diagnosis. More common in men > 60 years.
Etiology & Risk Factors
- Idiopathic. Risk factors include smoking, environmental exposures, and genetics (MUC5B mutation, telomerase mutations).
Clinical Symptoms
- Gradual onset of exertional dyspnea
- Non-productive (dry) cough
- Fatigue
- Digital clubbing (late sign)
Clinical Approach
Diagnosis
- High-Resolution CT (HRCT) of chest: 'Usual Interstitial Pneumonia' (UIP) pattern - honeycombing, traction bronchiectasis, peripheral and basilar predominance
- Pulmonary Function Tests (PFTs): Restrictive pattern (decreased TLC, decreased FVC, normal/high FEV1/FVC, severely decreased DLCO)
- Surgical lung biopsy (rarely needed if HRCT is classic)
Management
- Anti-fibrotic agents (Pirfenidone, Nintedanib) - slows disease progression but does not cure
- Supplemental oxygen
- Pulmonary rehabilitation
- Lung transplantation (the only definitive cure)
Complications
- Pulmonary hypertension
- Acute exacerbations (rapid decline)
- Respiratory failure