Which of the following is a cause of exudative pleural effusion?

Which of the following is a cause of exudative pleural effusion?

• A. Pneumonia
• B. Nephrotic syndrome
• C. Cirrhosis
• D. Hypothyroidism

Answer: (A)

Exudative pleural effusions arise from inflammation of the pleura or nearby lung tissue, leading to increased vascular permeability and leakage of protein-rich fluid into the pleural space. An infectious process like pneumonia fits this pattern because the inflammation from the infection drives the exudative fluid, often meeting criteria of high protein and elevated LDH in the pleural fluid. The other conditions typically cause transudative effusions, which result from systemic factors rather than local pleural inflammation. Nephrotic syndrome lowers plasma oncotic pressure from hypoalbuminemia, cirrhosis causes fluid to accumulate due to portal hypertension and low albumin, and hypothyroidism can produce effusions through metabolic and lymphatic changes, but not primarily through inflammatory exudation. Thus pneumonia is the best explanation for an exudative pleural effusion.

Exudative pleural effusions arise from inflammation of the pleura or nearby lung tissue, leading to increased vascular permeability and leakage of protein-rich fluid into the pleural space. An infectious process like pneumonia fits this pattern because the inflammation from the infection drives the exudative fluid, often meeting criteria of high protein and elevated LDH in the pleural fluid.

The other conditions typically cause transudative effusions, which result from systemic factors rather than local pleural inflammation. Nephrotic syndrome lowers plasma oncotic pressure from hypoalbuminemia, cirrhosis causes fluid to accumulate due to portal hypertension and low albumin, and hypothyroidism can produce effusions through metabolic and lymphatic changes, but not primarily through inflammatory exudation. Thus pneumonia is the best explanation for an exudative pleural effusion.