Desquamative interstitial pneumonia (DIP) is a type of interstitial pneumonia, a chronic lung inflammation characterized by air cavity mononuclear cell infiltration. DIP is a clinically and pathologically independent disease name, affecting smokers aged 30 to 40 years old, and most patients have shortness of breath. It is characterized by extensive desquamation and proliferation of alveolar cells in the alveolar cavity, which responds well to steroid hormones. Liebow et al. believed that it was an independent disease, but Sceding et al. believed that it might be a stage in the development of fibrosing alveolitis. Other authors found that the pathological changes in the lungs in cases of idiopathic interstitial pulmonary fibrosis, eosinophilic granuloma, pulmonary proteinosis, and long-term use of furazolidone in rheumatoid disease were similar to those in desquamative interstitial pneumonia.