| Self-limited inflammation | Drug-induced lung disease (acute onset) Hypersensitivity pneumonitis (short-term exposure) Sarcoidosis (distinct subset with usually acute onset) COP, DIP and LIP |
| Stable fibrotic disease | Drug-induced lung disease (residual fibrosis after cessation) Hypersensitivity pneumonitis (after prolonged exposure) Sarcoidosis (residuum of burnt-out fibrotic disease) Non-progressive pneumoconiosis after cessation of exposure (e.g. silicosis) NSIP |
| Major inflammation, risk of fibrotic progression | Drug-induced lung disease (unusually florid reactions) Hypersensitivity pneumonitis (usually continuing exposure) Sarcoidosis (prolonged severe inflammation) NSIP, COP, LIP and DIP |
| Inexorably progressive fibrosis | Drug-induced lung disease (continuing exposure) Hypersensitivity pneumonitis (antigen usually unknown) Sarcoidosis (small subset of patients) Progressive pneumoconiosis after exposure (e.g. asbestosis) UIP |
| Explosive acute diffuse lung disease | Drug-induced lung disease AIP |
COP: cryptogenic organising pneumonia; DIP: desquamative interstitial pneumonia; LIP: lymphocytic interstitial pneumonia; NSIP: nonspecific interstitial pneumonia; UIP: usual interstitial pneumonia; AIP: acute interstitial pneumonia.