Allergic rhinitis involves inflammation of the nasal mucosa triggered by an IgE-mediated response to allergens. It is very common, affecting about 40 million people in the US, with onset typically occurring in childhood. Symptoms include sneezing, rhinorrhea, nasal congestion and itchiness. Management involves allergen avoidance, pharmacotherapy like antihistamines and intranasal corticosteroids, and immunotherapy. Allergic rhinitis can negatively impact quality of life and is associated with increased risk of conditions like asthma and sinusitis.