Perception of dyspnea in children with asthma.

The subjective experience of discomfort in breathing, termed dyspnea (or breathlessness), is a symptom with multifactorial causes of highly complex and largely undefined psycho-physiologic mechanism(s). There are at least three discrete qualities of dyspnea likely corresponding to different types of respiratory stress and separate underlying mechanisms. Perception of dyspnea can be measured by diverse means; however, none of these scales has been standardized in children. In general, the same degree of bronchoconstriction causes various levels of perception of dyspnea in different patients. There are large discrepancies among patients in subjective rating of the severity of dyspnea and objective measurement of lung function. Since reporting symptoms is an integral part of therapeutic management of asthma, poor perception of dyspnea may lead to delayed diagnosis and undertreatment of the disease.