Bronchial hyperreactivity and history of wheezing in children

Abstract

Wheezing is a very common symptom in childhood and only partly associated with later bronchial hyperreactivity. On the other hand, asthma is often not diagnosed despite bronchial hyperreactivity and many years of wheezing.

Sustaining the Implementation of an Evidence-Based Guideline for Bronchiolitis

“…[16][17][18][19] In spite of the published evidence, these relatively aggressive therapies have remained prevalent. 10,16,18,[20][21][22][23][24][25][26][27][28] The persistent use of ␤ 2 -agonists in spite of their questionable efficacies has been justified, because 9% to 44% of patients with bronchiolitis patients are reported to subsequently progress to develop asthma 14,18,19,[26][27][28][29][30][31][32][33] and, in the first presentation with wheezing, might be demonstrating this fact. Our experience at Children's Hospital Medical Center (CHMC) supports the lower range of these estimates.…”

Asthma

“…Consequently, access to the mucosa and submucosa by inhaled molecules such as allergens, microorganisms, dusts, environmental pollutants and inflammatory mediators is made easier. Among those last named, superoxide anion has a particularly harmful effect on the airways with its highly destructive radicals [726]. The epithelial damage exposes intraepithelial mast cells, afferent nerve endings and, in particular, irritating vagal receptors to the combined action of various stimuli.…”

“…Many different lines of research agree that RSV-induced bronchiolitis is responsible for a subsequent asthmatic syndrome, persistent for many years after the primary infection. In particular, it is hypothesized that anti-RSV IgE production can constitute a marker for the predisposition to develop specific response to VRI of early and late infancy, able to trigger recurrent asthmatic episodes [453] (Table 11.29) [4,117,161,178,214,241,246,302,381,375,423,447,454,470,495,587,616,637,644,713,726,745]. Studies fail to clarify the pathogenesis of this higher prevalence of asthma in these subjects [585,587].…”

“…The other important question remaining to be clarified is that together with children in whom wheezing associated with atopy and BHR (development that is a prelude to asthma) began after the age of 2 [423], there are others with early onset of wheezing (<2 years), which ceases, more or less without consequences, at about 10-11 years of age [726], in relation with reduced airway development in this period, and with the particular vulnerability to VRIs [725]. Similarly, the age which should be taken as a reference has proved to be a relative factor [723].…”

“…For the prevalence of wheezing, see Tables 5.10 and 5.12.Wjst et al show that it is on the increase from 10.9% to 17.6% in the 1-to 3-year age group, then decreasing from 16.4% to 9.7% from 4 to 9 years [726], while others report figures of 60% [638] or 50% [383]. In this study, the children examined at birth and re-examined at the age of 3 or 6 based on the time of onset and pattern of wheezing symptoms were divided into three wheezing phenotypes: ∑ 19.9% with transient wheezing only in the first 3 years of life ∑ 15% with late-onset wheezing, not present in the first 3 years, (but with symptoms beginning between 3 and 6 years) ∑ 13.7% with persistent wheezing in the first 6 years of life.…”