Tuesday, June 14, 2005

Silicosis

Silicosis is a nodular fibrosis of the lungs. Its typically found in people exposed to free silica (SiO2) in their working areas, such as mining or stonecutting. Patients develop a progressive fibrosis of their lungs based on their exposure, and the disease can be fatal within two years. Silicosis has a wide range of presentation. Acute silicosis has profuse miliary infiltration or consolidation. Milder silicosis show small opacities and possible coalescence. The hilar nodes are the lymph nodes of the lungs, and they may become calcified. Hilar lymph nodes with an "egg shell" appearance are a classic presentation of silicosis on radiographs. The pulmonary nodules of silicosis, which are found in the upper lobes of the lungs, may lead to progressive massive fibrosis and subsequent restrictive and obstructive lung disease. This may lead to ventilatory failure. Patients with silicosis are more prone to develop Tuberculosis (Mycobacterium tuberculosis) and other atypical mycobacterial infections.(1)
Even ten to thirty years after exposure, silicosis can be asymptomatic. Patients can present with dyspnea, cough, or sputum production. Chest radiographs show small pulmonary nodules, from 1 mm to 10 mm, in the upper lobes of the lungs. Silicosis' complications include with lung cancer, chronic respiratory failure, and cor pulmonale. Patients should be treated for tuberculosis infections and other lung ailments. Other than for severe cases, prognosis is generally good for silicosis with possible mild respiratory symptoms.(2)

Medical Student Report
(1) Harrison's Online
(2) Hanley Pulmonology
McGraw-Hill's AccessMedicine

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