What is an intrinsic factor that can precipitate an asthma attack?

Allergens such as pollen or dust mites are considered intrinsic factors that can trigger an asthma attack. These allergens induce an immune response in individuals who are sensitive to them, leading to airway inflammation, bronchoconstriction, and increased mucus production. In the context of asthma, this immune reaction can result in symptoms such as wheezing, shortness of breath, and chest tightness.

Intrinsic factors generally refer to internal triggers specific to the individual, and allergens fall into this category as they are often linked to a person's unique allergic sensitivities. This can lead to chronic inflammation of the airways, making them more reactive to a range of stimuli. Recognizing allergens as these intrinsic factors is crucial in managing asthma effectively, which often entails avoiding exposure to known triggers and using appropriate medications to control symptoms.

The other choices represent different types of triggers that can cause asthma exacerbations but are usually classified as extrinsic factors. Cold air exposure can act as an environmental irritant, physical exercise can provoke symptoms in certain individuals, and respiratory infections can exacerbate asthma symptoms but are not specific to an individual's intrinsic factors.