Here's how allergies may contribute to asthma:

1. Inflammatory Response:

Both allergies and asthma involve an abnormal immune system response. In allergic reactions, the immune system reacts to allergens by releasing chemicals such as histamines. In asthma, there is inflammation of the airways, leading to increased sensitivity and reactivity. When allergies and asthma coexist, the inflammatory response triggered by allergens can contribute to the inflammation of the airways in the lungs.

2. Common Triggers:

Allergens that commonly trigger allergic reactions, such as pollen, mold spores, pet dander, and dust mites, can also act as triggers for asthma symptoms in susceptible individuals. Exposure to these allergens can lead to the narrowing of the airways (bronchoconstriction), increased mucus production, and difficulty breathing.

3. Allergic Sensitisation:

Individuals with allergies, especially those with allergic rhinitis (hay fever), are more likely to develop asthma. This progression is often referred to as the "atopic march." Allergic sensitization involves the immune system becoming hypersensitive to allergens, and this heightened sensitivity can extend to the lower respiratory tract, contributing to asthma development.

4. Rhinitis and Sinusitis:

Allergic rhinitis (inflammation of the nasal passages) and chronic sinusitis are common allergic conditions that can contribute to asthma. The inflammation in the upper airways can extend to the lower airways, leading to a more widespread inflammatory response and increased asthma symptoms.

5. Exacerbation of Existing Asthma:

For individuals already diagnosed with asthma, exposure to allergens can exacerbate existing asthma symptoms. Allergen exposure can trigger asthma attacks, characterized by coughing, wheezing, shortness of breath, and chest tightness.