5 Allergic Asthma and Aging (original) (raw)

Bronchial Asthma-Emerging Therapeutic Strategies 90 Elderly asthmatic patients mainly include those who have acquired the disease during childhood or adolescence and whose disease has progressed over time or is recurrent after periods of remission (elderly asthmatics, long life), but the first manifestations of asthma can occur even in late adulthood or after 65 years of age (the elderly, asthmatics, late-onset). These considerations, taken in isolation, have resulted in asthma being under-diagnosed and under-treated in elderly patients, which may be due to diagnostic misclassification. Underestimation of the prevalence of asthma may be due to confusion with COPD. In this chapter, after describing the basics of atopy and immune alteration of the immune system in the elderly, we will examine the flow characteristics of the pathophysiology of asthma and COPD, establish the basis for correct diagnosis of asthma, highlighting the confounding factors of diagnosis, and the importance of monitoring the clinical course, identifying areas for improvement. 2. Definition of asthma Scientific knowledge has changed the definition of bronchial asthma and is now defined as r e p o r t e d b y t h e N a t i o n a l I n s t i t u t e s o f H e a l t h (N I H) [ 1 ]. A s t h m a i s d e f i n e d a s a n inflammatory disorder of the airway associated with airflow obstruction and bronchial hyper-responsiveness, This definition replaces the previous definition of asthma in which only the airflow obstruction and the bronchial hyper-responsiveness was emphasized [2]. 2.1 Epidemiology The overall prevalence of asthma in children and adults varies in European countries, with estimates of 15%-18% in the United Kingdom, 7% in France and Germany, 4.4 Italy and of 1.9 in Albania [3]. Long considered a disease of childhood or young adulthood, its prevalence is now known to be similar in older people [4]. The incidence of newly diagnosed asthma in patients ≥ 65 years is 0.1%/years in a population based study done on Rochester residents [5]. Asthma may persist from childhood or have its onset in adult life. The primary variable for persistence and severity of asthma identified in longitudinal studies is the severity in childhood. However, common sense and everyday experience tell us that continued exposure to relevant indoor allergens is also important [6,7]. The studies also suggest that sensitization and exposure to outdoor allergens, result in more persistent and severe asthma [8]. The presence of atopy increases the incidence of asthma in children and may also increase the incidence in young adults. A cohort of college students evaluated for hay fever or asthma were followed up 23 years later. At the age of 40 years, about half of subjects who had asthma as freshmen continued to have asthma. Of these subjects, half (a quarter of the entire group) reported that they continued to have about the same frequency and severity of symptoms; very few were worse. During these 23 years, 5.2% of subjects who did not have asthma as freshmen developed asthma subsequently; the yearly incidence rate was 0.23%. The presence of positive skin test results or hay fever as freshmen did not affect the incidence of new cases of asthma as these subjects www.intechopen.com Allergic Asthma and Aging 91 grew older. Unfortunately, skin tests were not performed at the 23-year follow-up of middleaged adults, so it is not known whether these new case of asthma were allergic [9]. The incidence of asthma is the same in patients age 65 to 84 years as it is in younger adults [10]. However the disease may be more likely to persist and progress in severity. A crosssectional study of 242 patients with asthma age 65 and older found that 80% had irreversible obstruction; 20% of them were unable to achieve an FEV1 greater than 50% predicted. The authors concluded that only a part of this irreversibility is the result of airway remodeling from asthmatic inflammation [10]. The diagnosis of asthma may be more difficult in the elderly because of the high prevalence of other disorders that can have similar symptoms, and because airflow obstruction is often caused by chronic obstructive pulmonary disease [11].