Idiopathic Interstitial Pneumonias

Abstract

The idiopathic interstitial pneumonias (IIPs) are a group of diffuse lung diseases that often manifest clinically with increasing dyspnea and hypoxemia. In the most recent revision of the American Thoracic Society/European Respiratory Society statement on IIPs, the major IIPs are divided into 3 groups: chronic fibrosing conditions (usual interstitial pneumonia and nonspecific interstitial pneumonia); smoking-related conditions (respiratory bronchiolitis and desquamative interstitial pneumonia) and acute/subacute IIPs (cryptogenic organizing pneumonia and acute interstitial pneumonia). Although some of these patterns may be seen with other conditions (e.g, NSIP with collagen vascular disease), the term IIP only refers to the idiopathic variants. Interestingly, the smoking-related conditions (RB-ILD and DIP) are included in this idiopathic grouping despite their association with cigarette use.