BOX 2-1 Impact of Allergic Disease on Quality of Life
Allergic diseases can disrupt childhood education and family life and have a negative effect on quality of life.
Once a diagnosis of asthma is made, the contribution of allergy to asthma is of great interest. Allergy may be confirmed through either skin testing or measurement of specific IgE antibodies in blood samples, or both. The causal relationship between allergy and asthma is established by the individual's history (see Chapter 5). For example, asthma that occurs in the spring may be due to allergens from tree pollen. People with perennial asthma are often unaware of the allergens that trigger their disease. Current recommendations include environmental modification as an early step in asthma management (NHLBI, 1991).
The diagnosis of asthma in population-based studies has been made in a variety of ways. Diagnostic criteria may be influenced by the local language, customs, and definitions and by physician habits, questionnaires, and study objectives (Kryzanowski et al., 1990). Examples of the epidemiologic definition of asthma include a history of episodic or persistent wheezing, a physician diagnosis of asthma, evidence of reversible airflow obstruction on pulmonary function tests, evidence of bronchial hyperreactivity, or a combination