Desquamative interstitial pneumonia

Desquamative interstitial pneumonia
Other names	DIP
Chest computerized tomography scan showing diffuse ground-glass opacities with air-bronchograms in the upper lobes and the left lower lobe.
Specialty	Pulmonology

Desquamative interstitial pneumonia (DIP) is a type of idiopathic interstitial pneumonia featuring elevated numbers of macrophages within the alveoli of the lung.^[1] DIP is a chronic disorder with an insidious onset. Its common symptoms include shortness of breath, coughing, fever, weakness, weight loss, and fatigue. In more severe cases, it may lead to respiratory failure, chest pain, digital clubbing, cyanosis, and hemoptysis. Asymptomatic cases are rare.

DIP is often linked to cigarette smoking, environmental or occupational exposure, systemic disorders, and infections. Environmental risk factors include diesel or fire smoke, asbestos, and other chemicals. DIP has also been associated with certain drugs like marijuana, sirolimus, macrolides, nitrofurantoin, tocainide, and sulfasalazine. Disorders, such as hepatitis C, cytomegalovirus, systemic lupus erythematosus, connective tissue disease, and rheumatoid arthritis, have also been tied to DIP.

Diagnosis often requires surgical biopsy, especially when imaging or other tests provide non-specific results. High-resolution computed tomography (HRCT) can help identify the features of DIP. Differential diagnosis includes non-specific interstitial pneumonia, pulmonary Langerhans cell histiocytosis, respiratory bronchiolitis-associated interstitial lung disease, and hypersensitivity pneumonia. DIP is primarily treated by quitting smoking, but it may not be enough in all cases. In moderate to severe cases, corticosteroids are used. Severe DIP can be treated with lung transplants, but recurrence is possible. DIP has a favorable prognosis, with a mortality rate of 6-28% and a survival rate of 68%-94%.