Pneumonitis is best described as which of the following?

• A. Accumulation of liquid in the alveolar spaces
• B. Inflammation of the lung tissues
• C. Accumulation of blood in the pleural cavity
• D. Infection of the pleural space

Answer: (B)

Pneumonitis refers to inflammation of the lung tissue itself (the parenchyma). This means the target is the lung’s tissue and airways undergoing an inflammatory reaction, which can result from various irritants, hypersensitivity, or non-infectious causes. It is not about fluid accumulating in the alveolar spaces, which would describe edema or alveolar flooding; it is not about blood in the pleural cavity (hemothorax); and it is not an infection of the pleural space (empyema). So describing it as inflammation of the lung tissues best fits what pneumonitis denotes.