Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 9-21: Diffuse Interstitial Pneumonias + Key Features Download Section PDF Listen +++ ++ Presentation similar to usual interstitial pneumonitis (UIP) but occurs in younger patients Patients are invariably heavy smokers Usually occurs without symptoms or physiologic evidence of lung disease Prognosis is better than in UIP; median survival > 10 years + Clinical Findings Download Section PDF Listen +++ ++ Age 40–45 years Insidious dry cough with exertional dyspnea over months to years Diffuse parenchymal infiltrates + Diagnosis Download Section PDF Listen +++ ++ Pulmonary function test shows restriction with decreased DLCO, usually less severe than that seen in UIP High-resolution CT more likely to reveal diffuse ground-glass opacities and upper lobe emphysema Biopsy shows increased numbers of macrophages localized within the peribronchiolar space; alveolar architecture is preserved, honeycomb change and fibrosis are minimal + Treatment Download Section PDF Listen +++ ++ Spontaneous remission occurs in up to 20% of patients Smoking cessation is crucial Trial of prednisone, 1–2 mg/kg/day orally for a minimum of 2 months