Accuracy of symptom perception in asthma and illness severity

The inaccurate perception of airway obstruction is a risk factor in fatal asthma and a common problem in asthma management. Perceptual inaccuracy often has been attributed to airway pathophysiology. Accuracy is defined in terms of airway obstruction, reflected in lung function. The accuracy of symptom perception was investigated during induced airway obstruction. In Experiment 1, 30 children and adolescents with asthma underwent a histamine provocation test. In Experiment 2, 64 children and adolescents with asthma and 30 without asthma performed a physical exercise task. Ages ranged from 7 to 18 years. Lung function and self-reported dyspnea were measured in parallel. The results showed that dyspnea reporting was independent of lung function (Forced Expiratory Volume in 1 sec), asthma severity, and airway hyperresponsiveness. Participants with asthma but without airway obstruction reported significantly mote dyspnea than controls. It was suggested that dyspnea is a highly subjective experience with its magnitude determined by psychological and situational factors rather than airway pathophysiology.