Which best describes the etiology of asthma?

The etiology of asthma is best described as chronic inflammation of the airways. This chronic inflammation leads to a heightened sensitivity of the airways, which can result in their constriction and narrowing in response to various triggers. It is characterized by airway hyperresponsiveness, which contributes to symptoms such as wheezing, shortness of breath, chest tightness, and coughing.

This inflammation can be a result of various factors, including genetic predisposition and environmental exposures, such as allergens (like pollen) and irritants. However, while allergens may trigger asthma symptoms, they are part of a broader inflammatory process rather than the sole cause.

In contrast, the sudden onset of lung collapse refers to a different medical condition, such as a pneumothorax, and does not accurately reflect asthma's chronic nature. Allergic reactions may play a role in some individuals with asthma but do not encompass the full spectrum of its etiology. Exposure to infectious agents can lead to respiratory illness, but it does not specifically account for the underlying chronic inflammatory component central to asthma. Therefore, recognizing asthma primarily as a condition characterized by chronic airway inflammation provides a clearer understanding of its etiology and pathophysiology.