Asthma in childhood

摘要: Asthma is defined as an obstructive disease of the pulmonary airways resulting from spasm airway muscle, increased mucus secretion, and inflammation. The asthmatic individuals are hyperresponsive to a variety stimuli including cold air, atmospheric irritants, pharmacologically active chemicals, various drugs, hyperventilation. fundamental abnormality underlying hyperresponsiveness appears be genetically determined; two theories explaining have received most attention. One theory suggests that asthma due abnormal beta-adrenergic receptor-adenylate cyclase function with decreased adrenergic responsiveness. An alternate proposes cholinergic activity in defect disease. true prevalence has been difficult determine owing uncertainties regarding definition Prevalence populations children ranged 1.37% 11.4% or higher. Most studies report preponderance boys over girls, ratios varying 1.3:1 3.3:1. Risk factors for include history atopy, acute lower respiratory tract disease, parental cigarette smoking, bronchiolitis croup. spectrum illness beginning early life persisting, some cases, through adulthood. Signs may apparent first 2 yr often associated viral infections. Disproportionate narrowing peripheral static elastic recoil properties lung predispose infants young asthma. During midchildhood there tendency toward improvement, continued improvement during adolescence. goal management child reduce symptoms sufficiently so can regularly attend school, engage play activities, sleep night uninterrupted, while avoiding unacceptable levels adverse drug effects. Nonpharmacologic includes both avoidance environmental irritants behavioral approaches overcome emotional precipitants lead attacks. Pharmacologic treatment use four classes drugs: (1) adrenergics, (2) theophylline, (3) cromolyn, (4) corticosteroids. prognosis childhood good. Although remain indefinite periods time, reach state where they virtually free symptoms.