Poor perception of dyspnoea in children with undiagnosed asthma.

The aim of the present study was to establish the differences in dyspnoea perception between children with undiagnosed and diagnosed asthma. A cross-sectional community-based study was performed, which included a parental questionnaire on the child's respiratory health and testing of airway reversibility and bronchial hyperresponsiveness (BHR). "Diagnosed asthma" was defined by a physician's diagnosis of asthma. "Undiagnosed asthma" was defined by the presence of asthma symptoms combined with either airway reversibility or BHR without a physician's diagnosis of asthma. Only children with a positive BHR test were selected for further analysis. Perception of dyspnoea was assessed using the Borg scale and the visual analogue scale (VAS), plotted against the percentage fall in forced expiratory volume in one second and expressed as the slope of the regression line. Of the initial 1,758 participating children, 70 had undiagnosed asthma and 38 had diagnosed asthma. The Borg and VAS slopes in children with undiagnosed asthma were less steep than those of children with diagnosed asthma (Borg: 0.07 and 0.14, respectively; VAS: 0.06 and 0.11, respectively). Among children with bronchial hyperresponsiveness, those without a parent's report of physician's diagnosis of asthma had a worse perception of dyspnoea than children with diagnosed asthma.

Inhaled corticosteroids and growth of airway function in asthmatic children.

Airway inflammation and remodelling play an important role in the pathophysiology of asthma. Remodelling may affect childhood lung function, and this process may be reversed by anti-inflammatory treatment. The current study assessed longitudinally whether asthma affects growth of airway function relative to airspaces, and if so whether this is redressed by inhaled corticosteroids (ICS). Every 4 months for up to 3 yrs, lung function was assessed in 54 asthmatic children (initial age 7-16 yrs), who inhaled 0.2 mg salbutamol t.i.d. and 0.2 mg budesonide t.i.d. (beta2-agonist (BA)+ICS), or placebo (PL) t.i.d. (BA+PL) in a randomised, double-blind design. Measurements were carried out before and after maximal bronchodilation. Airway growth was assessed from the change of forced expiratory volume in one second and of maximal expiratory flows (at 60% and 40% of total lung capacity (TLC) remaining in the lung) relative to TLC, as measures of more central, intermediate and more peripheral airways. Growth patterns were compared with the longitudinal findings in 376 healthy children. Airway patency after maximal bronchodilation in patients on BA+PL remained reduced compared to healthy subjects, whereas in patients on BA+ICS a marked improvement was observed to subnormal. No differences between patients and controls could be demonstrated for growth patterns of central and intermediate airway function. Compliance with BA+ICS was 75% of the prescribed dose, resulting in significant, sustained improvement of symptoms and postbronchodilator calibre of central and intermediate airways to subnormal within 2 months, but postbronchodilator small airway patency remained reduced, though improved compared to patients on BA+PL. Anti-inflammatory treatment of asthmatic children is associated with normal functional development of central and intermediate airways. The persistently reduced postbronchodilator patency of peripheral airways may reflect remodelling, or insufficient anti-inflammatory treatment.