In the United States, almost 35 million people have allergic rhinitis or hay fever. Allergic rhinitis is an inflammation of the nasal airways caused by an allergic reaction to something in the environment like pollen, dust or animal dander. The symptoms can vary from mild to severe.

Allergic rhinitis is the sixth most common chronic illness in the United States and direct medical costs are estimated at $7 billion annually. Each year, medications alone cost more than $3 billion.

Allergic rhinitis is the result of a series of steps that ultimately release histamine: an allergen binds to a specific type of immunoglobulin called IgE, which then binds to histamine-containing cells resulting in the release of histamine. Histamine triggers the symptoms of allergic rhinitis — sneezing, red and watery eyes, swelling of the nasal passages and a production of copious mucus.

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