Asthma: Diagnosis and Management ____________________________________________________________
Exercise Exercise is a proven asthmagen in some individuals. Exercise- induced asthma (EIA) refers to airway changes following activ- ity, which distinguish it from chronic asthma. In patients with chronic asthma, symptoms surface any time, in response to one or more triggers. With EIA, the trigger is more obvious, as symptoms appear when the patient is engaged in exercise and can persist for several hours after activity ends. It is estimated that between 80% and 90% of patients with chronic asthma experience symptoms from exercise at some time [8; 9; 59]. It is very important to realize that any burst of exercise or sustained exercise can trigger asthma flare-ups; reactions can be immediate or delayed, in some cases occurring several hours later. The exact cause of EIA is unknown. One theory focuses on the loss of warmth and moisture from the airways during exercise. After the activity concludes, patients with asthma warm their airways four times faster than those with- out asthma; some researchers believe that this warming is a sign of edematous airways. Exercise-related airflow problems result in coughing, wheezing, and shortness of breath. The earliest symptoms, such as wheezing, may not be apparent at first because exercise stimulates the increased production of epinephrine, which can mask the symptoms associated with the onset of an attack. Patients with EIA usually begin to have difficulties about 10 minutes into strenuous activity or within 5 to 20 minutes of ending the activity [8; 9; 59]. Another theory suggests that the major cause of EIA is hyper- ventilation. In fact, the bronchial constriction that occurs during exercise in those with EIA may also be induced by hyperventilation, even in the absence of vigorous physical activity [59]. Some exercises are more likely than others to cause asthma. Team sports that require short bursts of energy (e.g., baseball, football) are less likely to cause symptoms than sports such as soccer or long-distance running that require ongoing activity. Cold weather activities (e.g., cross-country skiing, ice hockey) also tend to make symptoms worse. Swimmers are exposed to warm, moist air, which does not tend to trigger asthma symptoms. Walking, leisure biking, and hiking also are good activities for individuals with EIA [8; 9; 59]. Generally, patients with EIA would be categorized as having mild intermittent asthma and their treatment plans would reflect this categorization. Practitioners should discourage any patients known to experience EIA from engaging in high-risk activities without access to fast-acting medications. This is not to say patients with asthma should not be active. On the con- trary, the majority of individuals with asthma benefit greatly from daily exercise, as better physical conditioning generally results in decreased asthma symptoms. The trick is to map out a routine and group of exercises that work best for the patient.
Dieting patients with asthma should be taught that some packaged goods, including some recommended by several diet plans, contain sugar substitutes, food coloring, and preserva- tives, all of which have been associated with exacerbation of asthma symptoms in sensitive individuals [8; 19; 47]. Before any dietary treatment, investigation, or recommenda- tion is initiated, a physician or healthcare provider should be aware of assessed risks; referral to a dietician or nutritionist may also be necessary.
Physiologic Triggers Hormone Changes
The relationship between hormonal changes and asthma is unclear. However, there are types of asthma that are trig- gered by changes in hormone levels. The number of girls who develop asthma at puberty, when large amounts of estrogen are produced, is growing. A higher incidence of asthma among women, as compared to men, continues through reproductive years [8; 18]. Many women have reported that their asthma worsens when they menstruate. Indeed, research suggests that the decreased levels of progesterone and estrogen during menstruation alter the body’s water and salt balance and may negatively affect bronchial muscles and smooth muscles. A few studies concur that premenstrual hormone changes stimulate airway constric- tion [8; 47; 18]. Contraceptive pills and hormone replacement therapy (HRT) during menopause are being studied as possible asthma stimu- lants. A Harvard research team surveyed 23,035 women in the Nurses’ Health Study and revealed that asthma was twice as prevalent among women who took hormones for 10 years or more, during and after menopause, compared to those women who did not take HRT [58]. However, more research is necessary to discover how and when hormonal changes during the menstrual cycle or menopause affect lungs and asthma symptoms. Stress There was once a theory that asthma was the body’s way of com- municating emotions. The current understanding of asthma is that emotions and mental disorders do not cause asthma in oth- erwise healthy patients. However, there is evidence that strong emotions may arouse symptoms in individuals with asthma; extreme bouts of laughter or fear can cause bronchial lumens to narrow abruptly. Also, any activity that stresses the respira- tory system, including crying or shouting, can stimulate nerves to constrict bronchial lumens. If asthma seems worse during particularly stressful times, specific activities and medications may be used to reduce asthma symptoms [8; 9; 47]. Referral to a counselor, psychologist, or support group may be helpful for patients whose stress is prompting asthma symptoms.
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