Nasacort Allergy Nasal Spray Nasacort Allergy Nasal Spray treats the symptoms of allergic rhinitis (e.g. hayfever), including sneezing, itching, & having a blocked, stuffy or runny nose. It contains the corticosteroid triamcinolone acetonide, which means that it is a type of steroid. Nasacort Allergy Nasal Spray only works if used on a regular basis & may take 3 to 4 days to feel maximum relief.