A 68-year-old patient presents to the pulmonology clinic wit…
A 68-year-old patient presents to the pulmonology clinic with progressive dyspnea on exertion over 18 months and a persistent dry cough. Physical examination reveals bibasilar inspiratory crackles and digital clubbing. Pulmonary function tests show FEV1/FVC ratio of 0.82 with reduced total lung capacity. High-resolution CT reveals reticular opacities with honeycombing in the subpleural and basilar regions. Which condition is mostly the cause of his symptoms?