Update on the diagnosis and classification of ILD

The purpose of this review is to provide an update on the diagnosis and classification of interstitial lung disease (ILD), with a specific focus on newly described ILD subtypes and phenotypes. In addition, the strengths and limitations of the current approach to ILD diagnosis and management are discussed.

Idiopathic pleuroparenchymal fibroelastosis and acute fibrinous and organizing pneumonia are new entities that have been described in small case series. Undifferentiated connective tissue disease-associated ILD, smoking-related interstitial fibrosis, familial ILD, unclassifiable ILD, and subclinical ILD have also been better characterized in recent publications. New data regarding these conditions are summarized in this review. The multidisciplinary approach to ILD is reviewed, and complementary classification schemes are described that may help direct the management and improve prognostication of some ILDs.

ILDs are a large and heterogeneous group of diseases with several newly characterized subtypes and phenotypes. The current approach to ILD classification has limitations in some patients that can be minimized by considering complementary classification schemes.