Allergic respiratory disease, rhinitis and asthma, is estimated to affect more than 20% of people in the United States. Its frequency is increasing, and it is responsible for considerable morbidity and cost. The disease process, which usually starts during childhood or adolescence, is present for many years. Thus, allergic respiratory disease is common, prolonged, costly, responsible for significant symptoms, and adversely affects normal lifestyles. Treatment of allergic rhinitis and asthma includes identification and avoidance of precipitating triggers, symptomatic medication, and allergen immunotherapy. In addition to its application to treatment of allergic respiratory disease, immunotherapy also is an effective treatment for people allergic to stinging insects (venom hypersensitivity).