Get the facts on Allergic Rhinitis with this 100%-accurate animated video. Part of Focus Apps' Understanding Disease: Respiratory series, the Allergic Rhinitis app explains how an over-reaction of the immune system to substances such as pollens, dust particles, or chemicals leads to allergic rhinitis, commonly referred to as hay fever. Understand the immune system, its role in disease development, symptoms, and prevention and management of allergic rhinitis.