Which of the following is a common trigger for asthma?

The presence of allergens is a well-established and common trigger for asthma. Allergens such as pollen, dust mites, mold spores, pet dander, and certain foods can provoke an immune response in sensitive individuals. When these allergens are inhaled or come into contact with the mucous membranes in the airways, the immune system may overreact, leading to inflammation, bronchoconstriction, and increased mucus production. This chain of events results in the characteristic symptoms of asthma, including wheezing, coughing, shortness of breath, and chest tightness. Understanding that allergens can significantly impact asthma management highlights the importance of identifying and avoiding exposure to specific allergens for individuals with asthma.

While the other triggers listed can influence asthma symptoms, they are generally less prevalent or specific compared to allergens in the context of asthma exacerbations.