Pathophysiology of Asthma in Children

Asthma, an inflammatory airway disease, affects as many as six million children in the United States. The pathophysiology of asthma, which studies how normal respiration processes malfunction and cause disease, has five primary characteristics.

Airway Inflammation

• In children, environmental allergens and viral infections are the most common triggers for airway inflammation.

Bronchial Hyperresponsiveness

• The airways typically respond to stimuli such as dust and allergens by constricting as a way to limit exposure. Bronchial hyperresponsiveness is an exaggerated response, causing the airways to narrow quickly and significantly. Allergens, which play a significant role in childhood asthma, according to the National Asthma Education and Prevention Program, can cause hyperresponsiveness.

Airflow Obstruction

• Airflow obstruction refers to limitation of normal airflow into and out of the lungs. Causes of airflow obstruction include constricted airways, inflammation of the airways, or mucus plugs in the airways. Children's airways are very small, which exaggerates the impact of airflow obstruction.

Exercise-induced Asthma

• Exercise-induced asthma is a specific condition in which exercise triggers brochospasms and airway inflammation, likely caused by changes in humidity and temperature of air being breathed in. Because children are naturally mouth breathers, the humidification and temperature control functions of the nose are not as effective.

Early and Late Responses

• Asthma is characterized by two types of responses. The early response phase is an allergic-type reaction resulting in inflamed airways. The early response is followed by the late response phase in which the immune system prolongs inflammation.