Acute Exacerbation in Interstitial Lung Disease

Abstract

Acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) has been defined as an acute, clinically significant deterioration that develops within less than 1 month without obvious clinical cause like fluid overload, left heart failure, or pulmonary embolism. Pathophysiologically, damage of the alveoli is the predominant feature of AE-IPF which manifests histopathologically as diffuse alveolar damage and radiologically as diffuse, bilateral ground-glass opacification on high-resolution computed tomography. A growing body of literature now focuses on acute exacerbations of interstitial lung disease (AE-ILD) other than idiopathic pulmonary fibrosis. Based on a shared pathophysiology it is generally accepted that AE-ILD can affect all patients with interstitial lung disease (ILD) but apparently occurs more frequently in patients with an underlying usual interstitial pneumonia pattern. The etiology of AE-ILD is not fully understood, but there are distinct risk factors and triggers like infection, mechanical stress, and microaspiration. In general, AE-ILD has a poor prognosis and is associated with a high mortality within 6-12 months. Although there is a lack of evidence based data, in clinical practice, AE-ILD is often treated with a high dose corticosteroid therapy and antibiotics. This article aims to provide a summary of the clinical features, diagnosis, management, and prognosis of AE-ILD as well as an update on the current developments in the field.

Keywords: acute exacerbation; definition; diagnosis; idiopathic pulmonary fibrosis; interstitial lung disease; management.

Figure 1

Diagnostic approach to acute exacerbation in interstitial lung disease. Adapted from Ref. (10). Abbreviation: ILD, interstitial lung disease; GGO, ground glass opacity; CT, computed tomography.

Figure 2

HRCT of an acute exacerbation in IPF. Axial HRCT of a patient with IPF at the time of an acute exacerbation shows extensive bilateral ground-glass opacification. Abbreviation: HRCT, high resolution computed tomography; IPF, idiopathic pulmonary fibrosis.