Which statement best describes pulmonary fibrosis?

Which statement best describes pulmonary fibrosis?

• A. Acute bacterial infection causing patchy consolidation.
• B. Obstructive pattern with increased FEV1/FVC ratio.
• C. Preferential involvement of upper lobes with cavitation.
• D. Chronic progressive interstitial scarring from persistent inflammation causing restrictive lung disease, usually unknown cause.

Answer: (D)

Pulmonary fibrosis involves chronic scarring of the lung interstitium from ongoing inflammation, which makes the lungs stiff and less compliant. This leads to a restrictive pattern on lung function tests, with reduced total lung capacity and vital capacity, and a normal or increased FEV1/FVC ratio. Gas exchange worsens as the diffusion barrier thickens, so DLCO is decreased. Clinically, this presents with progressive shortness of breath and a dry cough, and exam may reveal fine Velcro-like crackles at the bases. Imaging often shows reticular markings and honeycombing in advanced disease. Most cases are idiopathic, meaning the cause is unknown. This description aligns with chronic, progressive interstitial scarring causing restrictive lung disease, usually without a known cause.

Pulmonary fibrosis involves chronic scarring of the lung interstitium from ongoing inflammation, which makes the lungs stiff and less compliant. This leads to a restrictive pattern on lung function tests, with reduced total lung capacity and vital capacity, and a normal or increased FEV1/FVC ratio. Gas exchange worsens as the diffusion barrier thickens, so DLCO is decreased. Clinically, this presents with progressive shortness of breath and a dry cough, and exam may reveal fine Velcro-like crackles at the bases. Imaging often shows reticular markings and honeycombing in advanced disease. Most cases are idiopathic, meaning the cause is unknown. This description aligns with chronic, progressive interstitial scarring causing restrictive lung disease, usually without a known cause.