Pathophysiology of Asthma Exacerbation

Pathophysiology of Asthma Exacerbation

• There are two phases of an asthma exacerbation: the early phase and late phase.
• The early phase is initiated by IgE antibodies that are sensitized and released by plasma cells.
• IgE antibodies respond to certain triggers in the environment, such as risk factors, and bind to high-affinity mast cells and basophils.
• When a pollutant or risk factor is inhaled, the mast cells release cytokines and eventually de-granulate.
• Released from mast cells are histamine, prostaglandins, and leukotrienes.
• Simultaneously, cytokines derived from the mast cell will signal other inflammatory cells and their mediators to the lung.
• The result is airway inflammation, increased vascular permeability, mucus secretion, bronchospasm, and wheezing.
• These events are referred to as the early asthmatic response because they occur within minutes.
• A major component of the early response is bronchospasm.

Key Components of Early Asthmatic Response

• Airway inflammation
• Increased vascular permeability
• Mucus secretion
• Bronchospasm
• Wheezing