Smoking-related interstitial lung disease: A narrative review

Although smoking-related interstitial lung diseases (SR-ILD) are a relatively rare group of entities, they are a relevant public health problem of growing importance, both because they affect young adults and because of their increasing prevalence in recent years due to increased tobacco consumption. In patients who smoke and have non-specific respiratory symptoms, SR-ILD should be ruled out, a term that encompasses a group of different entities in which the basis for diagnosis is the smoking history together with compatible respiratory functional findings, radiology and/or histology. An association has been established between tobacco smoke and a group of diseases that include respiratory bronchiolitis-associated interstitial lung disease (2%-3% of all ILD), desquamative interstitial pneumonia (<1%), Langerhans cell histiocytosis (3%-5%) and acute eosinophilic pneumonia. Smoking is considered a risk factor for idiopathic pulmonary fibrosis which has also been called combined fibroemphysema (5%-10% of all ILD); however, the role and impact of smoking in its development, remains to be determined. The likely interconnection between the mechanisms involved in inflammation and pulmonary fibrosis in all these processes often results in an overlapping of clinical, radiological, and histological features. In the absence of robust scientific evidence on its management, smoking cessation is the first measure to be taken into account. Although most diseases have a benign clinical course after smoking cessation, some cases may progress to chronic respiratory failure.