Which symptom is most commonly associated with allergic rhinitis?

Nasal congestion is the symptom most commonly associated with allergic rhinitis because this condition involves an inflammation of the nasal mucosa due to allergens such as pollen, dust mites, mold, or pet dander. When the immune system responds to these allergens, it triggers the release of histamines and other inflammatory mediators, leading to swelling and increased mucus production in the nasal passages. This response results in symptoms such as nasal congestion, sneezing, itching, and runny nose, making nasal congestion the hallmark symptom of allergic rhinitis.

In contrast, while ear pain, coughing, and facial swelling can occur with allergic rhinitis, they are not as universally characteristic of the condition. Ear pain may arise if congestion leads to Eustachian tube dysfunction, coughing may occur secondary to post-nasal drip, and facial swelling is typically more associated with conditions like sinusitis rather than allergic rhinitis alone. Thus, nasal congestion is the most prominent and defining symptom.