A 30-Year-Old Man With Cough, Dyspnea, and Upper Lobe Opacities

CASE PRESENTATION: A 30-year-old man presents with dry cough and dyspnea on exertion (modified Medical Research Council dyspnea scale of 3), with progressive worsening over several months. He denies other respiratory or cardiac symptoms such as wheezing, hemoptysis, thoracalgia, palpitations, or leg swelling. He also denies constitutional symptoms, namely fever, sweating, anorexia, or weight loss. The patient is a current smoker (five cigarettes per day), with no other significant exposures, diseases, or medications. He had no personal history of respiratory diseases or TB. Relevant family history included an aunt with nonspecified interstitial lung disease and lung transplant.