Which condition involves a chronic reaction to allergens?

Asthma is characterized by a chronic inflammatory reaction to various allergens, which can include pollen, dust mites, pet dander, and mold. In individuals with asthma, exposure to these allergens triggers inflammation and hyperresponsiveness in the airways, leading to symptoms such as wheezing, coughing, shortness of breath, and chest tightness.

The chronic nature of asthma means that individuals may experience recurrent episodes and varying degrees of airway obstruction, necessitating ongoing management and monitoring. Asthma can be influenced by genetic factors, environmental triggers, and overall respiratory health.

Other conditions listed do not primarily involve a chronic allergic response. Stress may exacerbate asthma symptoms but is not an allergic reaction itself. Pneumonia is an infection that leads to lung inflammation rather than a chronic allergic condition. Sinusitis involves inflammation of the sinuses, which can be caused by an infection or allergies but does not have the same chronic airway obstruction characteristics as asthma.