Diffuse lung disease: an approach to management.

Abstract

The term diffuse (interstitial) lung disease embraces a large number of disorders characterised by distinct cellular and extracellular infiltrates in the acinar regions of the lung (that is, distal to the terminal bronchiole). Some of these diseases present acutely whereas others have a subacute or chronic course: the infiltrate may result in tissue injury, as in cryptogenic fibrosing alveolitis, or cause little damage to the lung architecture, as in pulmonary eosinophilia. Because diffuse lung disease particularly affects the peripheral part of the lung, chest radiographs usually show widespread shadows of various types, and in clinical practice this is the commonest starting point for diagnostic evaluation: a clinician is consulted by a (usually breathless) patient with a chest radiograph that shows widespread pulmonary shadows. About one in every 3000-4000 of the population in Britain has diffuse lung disease, and about 3000 people die each year from it.1 Cryptogenic fibrosing alveolitis is the most common diffuse lung disease and carries the worst prognosis: in all studies half of patients are dead within five years of presentation despite treatment, and only a quarter show an apparent response to treatment.*RF 1a4* In the United Kingdom mortality from fibrosing alveolitis is increasing and approaching 1500 a year.5 #### Diffuse (interstitial) lung disease ##### Cause known ##### Cause unknown Despite these disturbing figures, a recent survey of the management of fibrosing alveolitis in three regions in Britain revealed that few patients underwent investigations to confirm the diagnosis.6 Transbronchial biopsy …