Allergic rhinitis can lead to a sinus infection, according to the American Academy of Allergy, Asthma & Immunology. Allergic rhinitis can cause nasal passages to swell, and the swelling prevents the sinuses from draining, which increases a person's risk of developing a secondary infection.
Sinus infections generally take several methods in order to effectively treat them, states the American Academy of Allergy, Asthma & Immunology. Among them are medicines that promote sinus drainage by reducing the inflammation present and medicines to control allergy symptoms. If bacteria are present, then a person may have to take antibiotics for a time. Additionally, breathing hot air and saline rinses can also help treat sinus infections.