Eosinophilic asthma (e-asthma) is a severe subtype of asthma characterized by high levels of eosinophils, a type of white blood cell, in the airways. These elevated eosinophil levels contribute to airway inflammation and increased asthma symptoms.
Understanding Eosinophilic Asthma
Eosinophils are a normal part of the immune system, playing a role in fighting off infections and parasites. However, in e-asthma, these cells become overactive and cause inflammation in the lungs, leading to:
- Airway narrowing: The inflamed airways become constricted, making it difficult to breathe.
- Mucus production: Increased mucus production further clogs the airways.
- Increased sensitivity: The airways become more sensitive to triggers like allergens, pollutants, and irritants.
Key Characteristics of Eosinophilic Asthma
Here are some key features that distinguish eosinophilic asthma from other types of asthma:
- High eosinophil count: This is the defining characteristic. Eosinophil levels can be measured in blood, sputum, or airway tissue.
- Severe symptoms: People with e-asthma often experience more severe symptoms, including frequent asthma attacks.
- Poor response to standard treatments: Traditional asthma medications like inhaled corticosteroids (ICS) may not be as effective in managing e-asthma.
- Later onset: E-asthma is more likely to develop in adulthood.
Symptoms of Eosinophilic Asthma
The symptoms of e-asthma are similar to those of other types of asthma but may be more severe:
- Wheezing
- Shortness of breath
- Chest tightness
- Coughing (especially at night or early morning)
Diagnosis of Eosinophilic Asthma
Diagnosis involves:
- Pulmonary function tests: To assess lung function.
- Sputum and blood tests: To measure eosinophil levels.
- Medical history and physical exam: To evaluate symptoms and rule out other conditions.
Treatment Options for Eosinophilic Asthma
Treatment focuses on reducing eosinophil levels and controlling airway inflammation. Options include:
- Inhaled corticosteroids (ICS): Although less effective than in other types of asthma, they're still often used.
- Long-acting beta-agonists (LABAs): Used in combination with ICS to open airways.
- Biologic therapies: Targeted medications that specifically block the action of eosinophils or other inflammatory pathways. Examples include anti-IL-5 and anti-IL-5Rα antibodies. These are often prescribed for severe cases.
- Oral corticosteroids: Used for short-term control of severe symptoms, but long-term use is avoided due to side effects.
Conclusion
Eosinophilic asthma is a specific and often more severe type of asthma driven by high levels of eosinophils in the airways. Diagnosis involves identifying elevated eosinophil counts, and treatment strategies often involve biologic therapies to target eosinophil activity.
