What occurs in the lung parenchyma during acute exacerbations of asthma?

During acute exacerbations of asthma, inflammatory cell infiltration occurs in the lung parenchyma. This process is characterized by the accumulation of various immune cells, including eosinophils, mast cells, and T lymphocytes, which play crucial roles in the inflammatory response associated with asthma. The presence of these inflammatory cells leads to increased production of cytokines and other mediators, contributing to airway hyperreactivity, mucus production, and bronchoconstriction, which are hallmark features of an asthma exacerbation.

The infiltration of these cells results in swelling of the airway walls and narrowing of the airways, leading to difficulties in breathing. This acute inflammation differentiates asthma exacerbations from other processes that might affect the lungs, such as chronic conditions that lead to fibrosis, which is more relevant in conditions like pulmonary fibrosis or advanced chronic obstructive pulmonary disease (COPD).

In summary, the correct answer reflects the immediate inflammatory response that is central to the pathophysiology of an acute asthma exacerbation.