This issue of Immunology and Allergy Clinics of North America, guest edited by Dr. Jonathan A. Bernstein, is devoted to Rhinitis. Articles in this issue include: Rhinitis Subtypes, Endotypes, and Definitions; Allergic Rhinitis: Burden of Illness, Quality of Life and Control; Allergic Rhinitis: Mechanisms of Action; Allergic Rhinitis: Diagnosis; Allergic Rhinitis: Treatment; Non-allergic Rhinitis: Mechanism of Action; Non-allergic Rhinitis: Diagnosis; Non-allergic Rhinitis: Treatment; Localized Allergic Rhinitis; Occupational Rhinitis; Rhinitis in the Elderly; Complications of Rhinitis; Allergic Rhinitis: Environmental Determinants; Non-allergic Rhinitis: Environmental Determinants; and Novel, Alternative, and Controversial Therapies.