Cigarette smoking is a recognized causative agent or precipitant of specific diffuse
lung diseases characterized by bronchiolar and interstitial lung inflammation. Respiratory
bronchiolitis-associated interstitial lung disease and pulmonary Langerhans cell histiocytosis
are now considered smoking-induced diffuse lung diseases. Desquamative interstitial
pneumonia is also recognized as a smoking-induced interstitial pneumonia in most cases.
These disorders affect relatively young adult smokers and may be progressive. Although
distinguishable by histopathological and radiographic features, significant overlap
occurs in many cases with chest radiography and lung histology showing overlapping
features of smoking-related bronchiolar and interstitial lung injury. Cigarette smoking
is also recognized as an important precipitant of many acute eosinophilic pneumonia
cases. Smokers are at higher risk of developing fibrotic interstitial lung diseases
such as idiopathic pulmonary fibrosis and rheumatoid arthritis–associated interstitial
lung disease. Certain smokers also develop combined emphysema and lung fibrosis. The
avoidance of primary and second-hand cigarette smoke is a critical component of management
for patients afflicted with these smoking-induced diffuse lung diseases. The role
of corticosteroids and other immunosuppressive treatments in the management of smoking-related
interstitial lung diseases remains poorly defined and should be reserved for individuals
with progressive disease despite smoking cessation. Understanding mechanisms by which
tobacco induces diffuse lung pathology is critical in the pursuit of novel therapeutic
approaches for these diseases.
Keywords
respiratory bronchiolitis - desquamative interstitial pneumonia - interstitial lung
disease - smoking - pulmonary Langerhans cell histiocytosis - acute eosinophilic pneumonia.
