19.1 : 哮喘：发病机制和治疗

Asthma, a chronic respiratory condition, entails airway inflammation, hyper-reactivity, and reversible obstruction of the airways.

It is categorized as allergic, triggered by allergens like dust, mites, and pet dander,  and non-allergic, induced by cold air or intense emotions.

Symptoms of asthma include wheezing, shortness of breath, chest tightness, and sleep disturbances.

The pathogenesis of asthma involves an immune response in genetically predisposed individuals.

It begins with the sensitization phase, where the initial exposure to an allergen prompts the immune system to produce IgE antibodies. These antibodies bind to mast cells in the airway mucosa, priming them.

Re-exposure to allergens triggers the release of inflammatory mediators, causing bronchial contraction, mucus secretion, and vascular leakage.

Hours later, a late-phase response occurs, involving the influx of inflammatory cells and the release of interleukins, which sustains bronchoconstriction, inflammation, and mucus production.

The management of asthma mainly relies on bronchodilators and corticosteroids.