Up to 30 percent of adults and up to 40 percent of children, experience the annoying nasal symptoms of allergic rhinitis. These include nasal discharge, itching, sneezing, congestion and pressure. Many cases can be classified into a specific syndrome:
• Allergic rhinitis caused by a variety of allergens
• Non-allergic rhinitis caused by nasal irritants such as smoke or strong smells
• Infectious rhinitis, usually caused by viral infection