What is the typical response of sinuses in allergic rhinitis?

In cases of allergic rhinitis, the typical response of the sinuses involves inflammation and blockage accompanied by thick secretions. This reaction occurs due to the body's immune system responding to allergens such as pollen, dust mites, or pet dander. When these allergens are encountered, the immune system releases histamines and other inflammatory mediators, which lead to swelling of the nasal and sinus linings. This inflammation results in a blockage of the sinus passages and the production of thick mucus, which can contribute to congestion and discomfort.

The other options do not accurately describe the typical sinus response in allergic rhinitis. While infections can sometimes lead to sinus enlargement, they are not the primary response in allergic scenarios. Reduced sensitivity to allergens does not align with allergic rhinitis, which is characterized by heightened sensitivity. Excessive dryness is also contrary to the common presentation, as allergic rhinitis usually results in an increase in mucus production rather than dryness. Thus, the correct answer reflects the typical physiological changes that occur in the sinuses during allergic rhinitis.