interstitial pneumonia, a condition of diffuse, chronic inflammation of the lungs beyond the terminal bronchioles, characterized by fibrosis and collagen formation in the alveolar walls and by the presence of large mononuclear cells in the alveolar spaces. The symptoms are progressive dyspnea, clubbing of the fingers, cyanosis, and fever. The disease may result from a hypersensitive reaction to busulfan, chlorambucil, hexamethonium, or methotrexate. It may also be an autoimmune reaction, because it often accompanies celiac disease, rheumatoid arthritis, Sjögren’s syndrome, and systemic sclerosis. X-ray films of the lungs show patchy shadows and mottling, as in bronchopneumonia. Later stages of the disease reveal bronchiectasis, dilation of the bronchi, and shrinkage of the lungs. Treatment includes bed rest, oxygen therapy, and corticosteroids. Most patients die within 6 months to a few years, usually as a result of cardiac or respiratory failure. Also called diffuse fibrosing alveolitis, giant cell interstitial pneumonia, Hamman-Rich syndrome. Compare bronchopneumonia.
