Predicting asthma treatment outcome at diagnosis: the role of symptom perception during a histamine challenge test

In asthma, many treatment decisions are dependent upon patient perception/patient report of asthma symptoms. Discrepancies between patient perception of asthma symptoms and objective indicators of pathophysiology are widespread and can hinder asthma treatment. Early detection of problems in asthma symptom perception may be a first step to help these patients. We investigated the predictive value of symptom perception during a histamine challenge test (HCT) at asthma diagnosis for patient-rated outcome of asthma treatment 3 months later.

In a prospective observational study, persons with asthma (N = 60) showing bronchial hyperresponsiveness in a HCT completed questions on asthma symptoms and negative affectivity (NA). The HCT was extended with an ambiguous situation suggesting asthma symptoms despite physiological recovery. Lung function (forced expiratory volume in 1 second (FEV(1))) and symptom ratings were measured during the test (after each histamine dosage), and we constructed several measures of asthma symptom perception based on FEV(1) and symptom ratings. Three months later, 30 participants completed questionnaires on asthma control and asthma-related quality of life.

Symptoms reported during HCT predicted worse asthma control and quality of life 3 months later. The prospective association between symptoms during HCT and asthma control remained significant when controlling for NA and baseline lung function. These effects were strongest for symptoms during ambiguous situations.

Higher symptom levels at the start of the HCT and during recovery may reflect a tendency to inaccurately perceive asthma symptoms in ambiguous situations. Assessing symptoms during diagnostic challenge tests can help predict problems with asthma treatment.