Flomist Nasal Spray is a widely prescribed medication used to treat symptoms of nasal allergies, such as congestion, sneezing, and runny nose. It’s especially effective for seasonal allergic rhinitis and perennial allergic rhinitis. Flomist Nasal Spray is used for managing the nasal symptoms of seasonal, perennial allergic and non-allergic rhinitis in adult and pediatric patients aged four years and older. Flomist : Uses, Dosage, Side Effects, Food Interaction & FAQ . Flomist nasal spray is used for the treatment of the symptoms of seasonal and perennial allergic rhinitis in Flomist nasal spray is used for the management of allergic rhinitis. It also relieves Seasonal allergies including sneezing, runny, stuffy nose, watery eyes, etc.