Bronchial asthma is a respiratory condition characterized by chronic allergic inflammation of the airways (the pathways through which air travels during breathing), caused by environmental allergens such as dust mites and mold, as well as various other risk factors. This inflammation leads to the enlargement and contraction of airway smooth muscles, resulting in airway narrowing and repeated episodes of coughing, wheezing (whistling or squeaky sounds), and shortness of breath. The narrowed airways can partially recover either spontaneously or with treatment (a property known as reversibility). However, if left untreated or if treatment is discontinued based on self-judgment, persistent airway inflammation may lead to structural changes in the airways, rendering them incapable of returning to their original state. In such cases, the response to treatment diminishes, asthma symptoms become more frequent, and the condition may worsen. Early and accurate diagnosis, followed by the initiation of long-term control medications such as inhaled corticosteroids to suppress airway inflammation, is essential. Continuing treatment even after symptoms subside is crucial to effective management.

Diagnosis is made comprehensively based on symptoms and various diagnostic evaluations.

• Symptoms・・・Cough, wheezing, shortness of breath, etc.
• Tests・・・Exhaled NO (nitric oxide) test, pulmonary function test, airway resistance test, airway reversibility test, airway irritability test, peak flow value measurement, blood test (peripheral blood eosinophil count, non-specific IgE, specific IgE), induced sputum test, etc.

Asthma treatment includes long-term control medications to manage daily symptoms and rescue medications to relieve asthma attacks.

Rescue Medications: These include inhaled short-acting β2 agonists (SABAs) and systemic corticosteroids administered orally or intravenously.

Long-term Control Medications: The cornerstone of long-term management is inhaled corticosteroids (ICS), which have a strong anti-inflammatory effect on the airways. Depending on the severity of the condition, additional medications may be used, such as bronchodilators (long-acting β2 agonists or sustained-release theophylline) to widen the narrowed airways, and leukotriene receptor antagonists.

For severe cases, biologics targeting key molecules involved in asthma pathophysiology (e.g., IgE, IL-5, IL-4, IL-13, and TSLP) have recently become available. These biologics, including Xolair®, Nucala®, Fasenra®, Dupixent®, and Tezspire®, are administered via subcutaneous injection every 2 weeks to 2 months and have shown significant efficacy.

Finally, it is important to receive an appropriate diagnosis at an early stage and to continue long-term controller medications such as inhaled steroids. If symptoms do not resolve with such treatment, we recommend a full examination and treatment at a specialized facility.