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Recent Discoveries in Preventing and Controlling Childhood Asthma
of 3,473 children were included. Multifaceted interventions appeared prevention of second-hand smoking at home is very important,
to have a significant effect whereas monofaceted interventions did particularly in families at risk of asthma, so new interventions that are
not. This effect was evident for both children below five years of age specifically targeted at stopping passive smoking exposure in children
(odds ratio [OR] 0.73 versus 1.22) and children five years of age or are urgently needed. It is evident from some studies that such
older (OR 0.52 versus 0.93). A Cochrane review of this meta-analysis interventions have the highest chance of success with an individual,
is under way.
42
family-tailored approach that includes education, assessment of
barriers and motivational and confrontational interviewing.
52–54
The ‘oldest’ multifaceted intervention study is the ‘Isle of Wight’
study.
43
In a pre-natally started study with 120 children genetically Another interesting risk factor for the development and severity of
predisposed to atopy, the effectiveness of an intervention with asthma that may be influenced is being overweight/obesity. Obesity
breastfeeding/hypoallergenic feeding and measures towards the and being overweight pose a major risk for several chronic diseases,
reduction of house dust mite exposure (acaricide treatment) was including type 2 diabetes, cardiovascular disease and probably also
assessed. The development of allergic diseases was measured in a asthma. A recent meta-analysis demonstrated an increased risk of the
blinded fashion at two, four and eight years. At eight years, the development of asthma in overweight children.
55
Obesity is related to
intervention had a significant positive effect on the development of more severe asthma.
56
Two studies in adults found that interventions
asthma (OR 0.24), eczema (OR 0.23), allergic rhinitis (OR 0.42) and directed towards weight reduction and physical exercise are of help
allergic sensitisation (OR 0.13). The Canadian Childhood Asthma in improving asthma symptoms, exacerbation rate, lung function and
Primary Prevention (CCAPP) study was a randomised controlled trial quality of life.
57,58
Such studies have not yet been performed in
that established the effectiveness of a combined intervention with children. The working mechanism of weight reduction on asthma may
measures directed towards diminished allergen exposure to house be: a direct effect on airway mechanics and lung function; less
dust mite and pets, prevention of passive smoking, promotion of production of adipokines from fat tissue with less allergic
breastfeeding and postponing solid foods.
44
The intervention started sensitisation and airway inflammation; and a decrease in gastro-
pre-natally and 545 high-risk children were randomised to either an oesophageal reflux. Effective weight-reduction programmes have
intervention group or a control group. At seven years of age, 469 been reported in children.
59,60
It is important that new intervention
children were contacted and 380 were further examined. The studies directed towards weight reduction and increased physical
prevalence of doctor-diagnosed asthma by the ‘paediatric allergist’ activity are performed in children with asthma.
was significantly lower in the intervention group compared with the
control group (14.9 versus 23.0%), but no difference was found for There are indications that allergen immunotherapy is of use in the
allergic rhinitis, eczema, positive skin tests and bronchial hyper- prevention of asthma in at least some children who are at risk.
reactivity. Other examples of multifaceted intervention studies of The effect of subcutaneous immunotherapy (SCIT) on the primary
shorter duration are the NAC Manchester Asthma and Allergy Study prevention of asthma was investigated in the European Preventive
(NACMAAS) study and the Prevention of Asthma in Children Allergy Treatment (PAT) study.
61
A total number 208 children between
(PREVASC) study.
45,46
More multifaceted intervention studies of six and 14 years of age with allergic rhinoconjunctivitis and a positive
sufficient duration aiming at the primary and secondary prevention of skin test for grass pollen and birch pollen were selected from six
asthma are needed. In the future, genetic profiling may be of help in European paediatric centres. Children with concomitant asthma were
selecting the children at highest risk of asthma. excluded. Patients were randomised into two groups: weekly
subcutaneous injections with grass pollen/birch pollen during a
‘New’ Targets for Prevention of Asthma – starting phase of 15–20 weeks followed by six-weekly injections
Passive Smoking, Overweight/Obesity during a maintenance phase of three years or control group (no
and Immunotherapy? placebo). The percentage of children with asthma in the SCIT group
In these multifaceted intervention studies it was striking that was 32% (19/60), which was significantly lower than the 80% (32/40)
exposure to passive smoking was the most difficult factor to influence in the control group. Also, the development of bronchial hyper-
and that the compliance of the parents to this preventative measure reactivity in the second and third year of the intervention was more
was low.
44,46,47
In multifaceted intervention studies, parents seem to favourable than in the control group. An analysis after five years
choose the easiest components of the preventive measures. This is showed that this intervention effect was still significant (OR 2.68). A
disappointing as the health risks of passive smoking are substantial: drawback is that the study was not blinded. In another open,
on average, children have a 1.2–1.6 higher risk of respiratory randomised study over three years, intervention with sublingual
complaints and infections, varying from airway infection such as immunotherapy in children with allergic rhinoconjunctivitis was
bronchitis and pneumonia to even more serious events such as accompanied by less development of asthma.
62
The methodological
sudden infant death syndrome and meningococcal septic shock concerns of these studies are: no blinding, no placebo group and a
syndrome.
48
Passive smoke exposure may contribute to the selected patient population. Nevertheless, these studies are intriguing
development of asthma and can increase the severity of asthma,
49,50
and give an indication that immunotherapy may prevent asthma in at
particularly in children with a positive family history. We recently least some patients. However, more blinded randomised controlled
demonstrated that children between zero and two years of age with trials are necessary on this topic.
a positive family history of asthma and an exposure to passive smoke
had an almost six- to seven-fold higher risk of ‘wheezing ever’ and Improved Control of Childhood Asthma by
‘attacks of wheezing’ than children without.
51
Exposure in utero is Including Non-invasive Assessments of
particularly harmful: children are born with a lower birth-weight and Airway Inflammation – Does It Work?
have diminished airway dimensions and lung function.
48
As the Since the release of the Global Initiative For Asthma (GINA) guidelines,
deleterious effects of passive smoking in children are evident, several Asthma Insights and Reality (AIR) surveys worldwide assessed
EUROPEAN RESPIRATORY DISEASE 17
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