Editors ADVANCES IN IMMUNOLOGY

Allergic rhinitis is characterized by episodes of sneezing, itching, rhinorrhea, and nasal obstruction. Perennial allergic rhinitis should be distinguished from nonallergic, noninfectious forms of rhinitis, such as idiopathic (“vasomotor”) rhinitis, nonallergic rhinitis with eosinophilia syndrome, hormonal rhinitis, drug-induced rhinitis, and food-induced rhinitis. The treatment of allergic rhinitis (and other aller-gic diseases) consists of allergen avoidance (whenever possible and practical), antiallergic medication, and immunotherapy for specific allergens, which is also called hyposensitization or desensitization. Currently, the drugs usually used to treat allergic rhinitis are an-tihistamines and anticholinergic agents (for the relief of symptoms) and topical corticosteroids (to suppress allergic inflammation). Histamine