A lung disease caused by inhalation of silica.
Silicosis is the most common chronic occupational lung disease in the world.
Silica occurs in both crystalline and amorphous forms. Crystalline form is more fibrogenic.
Inhalation phagocytosis by macrophages activation of inflammasome by phagocaytosed particles release of inlammatory mediators
- A central area with whorled collogen fibers
- Peripheraly dust-laden macrophages
Chest radiographs typically show a fine nodularity in the upper zones of the lung. Pulmonary functions are either normal or only moderately affected early in the course, and most patients do not develop shortness of breath until progressive massive fibrosis supervenes. The disease may continue to worsen even if the patient is no longer exposed. Silicosis is slow to kill, but impaired pulmonary function may severely limit activity. It is associated with an increased susceptibility to tuberculosis. This may be because crystalline silica inhibits the ability of pulmonary macrophages to kill phagocytosed mycobacteria. The onset of silicosis may be slow and insidious (10 to 30 years after exposure; most common), accelerated (within 10 years of exposure) or rapid (in weeks or months after intense exposure to fine dust high in silica; rare). Patients with silicosis have double the risk for developing lung cancer.