Which class of medication is primarily used to treat allergic rhinitis?

Antihistamines are primarily used to treat allergic rhinitis because they work by blocking the action of histamine, a substance in the body that causes allergic symptoms such as sneezing, runny nose, and itchy eyes. By inhibiting histamine's effects, antihistamines effectively alleviate the common symptoms associated with allergies, providing relief and improving quality of life for those affected.

Corticosteroids, while also effective in managing allergic rhinitis, are typically reserved for more severe cases or when antihistamines alone do not provide adequate relief. They work by reducing inflammation in the nasal passages, which can help control more persistent symptoms.

Beta-agonists are primarily used for treating respiratory conditions such as asthma, rather than allergic rhinitis. They function by relaxing bronchial smooth muscle, which does not directly address the specific symptoms of allergic rhinitis.

Antibiotics are used to treat bacterial infections, not allergies. Their use in the context of allergic rhinitis is inappropriate as allergic reactions are not caused by bacteria.

By focusing on the mechanism of action of antihistamines and their direct role in alleviating allergic reactions, it's clear why they are the first-line treatment for allergic rhinitis.