This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Social & Preventive Medicine
[{'content': 'Acute silicosis clinical manifestation is – \nSelect and explain. \nA. Pulmonary alveolar proteinosis, B. Hypersensitivity penumonitis, C. Hypersensitivity pneumonia, D. Forms nodules and causes pneumoconiosis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Silicosis\n\nSilicosis is a lung disease caused by inhalation of crystalline silicon dioxide (silica).\nCurrently, it is the most prevalent occupational disease in the world.\nThere are three types of silicosis -\n\ni) Acute silicosis\n\nResults from short-term exposure to a very large amounts of silica.\nA subset of acute silicosis is silicoproteinosis the chest radiographic appearance of which mimic pulmonary alveolar proteinosis.\nA miliary picture with very small round opacities may also occur in lower lung fields.\n\nii) Accelerated silicosis\n\nOccurs after exposure to large amounts of silica over a shorter period of time (4-8 years).\nInflammation, scarring and symptoms progress faster than chronic silicosis.\n\niii) Chronic silicosis\n\nResults from long term exposure (more than 20 years) of low amounts of silica dust.\nNodules in upper zones of lung.\nFibrotic lesions in hilar lymph node & pleura\n\t\xa0Progressive massive fibrosis\nIncreased susceptibility of TB → silicotuberculosis', 'role': 'assistant'}]