Which of the following is a symptom of Empyema?

Empyema is characterized by the accumulation of pus in the pleural cavity, which is typically a result of an infection. The presence of purulent pleural exudates is a key symptom of empyema. In cases of empyema, the pleural fluid becomes infected, leading to the formation of pus that can contain bacteria, inflammatory cells, and other debris. This scenario is indicative of a more severe complication compared to a simple pleural effusion or other non-purulent conditions.

The other options, while related to pleural conditions, do not specifically highlight the presence of pus, which is essential for diagnosing empyema. Pleural thickening can occur due to various reasons and is not specific to the presence of infection. A dry cough may accompany many respiratory conditions, but again, it does not indicate the presence of empyema specifically. Pleural effusion refers to fluid accumulation in the pleural space, which can be a feature of several conditions, not just empyema, and does not specifically denote the infectious nature of the fluid.

Therefore, the presence of purulent pleural exudates directly signifies the pathological condition of empyema, making it the correct symptom associated with this disease.