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Asthma
Worldwide, large problems exist with the control of asthma in both children demonstrated at least some diagnostic value of FeNO for a
adults and children. Several cross-sectional surveys have diagnosis of asthma.
33,34
FeNO may not be elevated in children with
demonstrated that actual levels of asthma control fall far below the non-atopic asthma and the question is whether FeNO is specific
goals of national and international guidelines.
16–18
What are the reasons enough for asthma to be of large diagnostic value in this specific age
for this discrepancy? Is monitoring of inflammatory parameters in our group. Exhaled breath condensate (EBC) is a relatively new technique
patients one of the solutions for better asthma control? in children.
31
Exhaled breath of children is collected and cooled in a
condenser system. EBC contains water vapour and respiratory
There is increasing interest in the inflammatory processes in small, solutes released from the epithelial lining fluid (ELF) of the airway
peripheral airways in asthma.
19
A number of inhaled corticosteroids epithelium.
35
Recently, we described a newly developed highly
with extra-fine particle size are currently available.
20,21
What evidence efficient condenser system with a breath re-circulation unit, which is
do we have that these new inhaled corticosteroids are more capable especially useful in pre-school children.
36
The success rate of EBC
of treating peripheral airway inflammation in children? Should these collection in two- to three-year-old children with this device is
new inhaled corticosteroids be used as a first-line therapy? currently 90–95%. In a pilot study with 70 pre-school children we
found lower tumour necrosis factor (TNF)-α and elevated Th2/Th1
In this article we will deal with several of these questions. A number cytokine ratios in EBC of children with probably allergic asthma
of new developments and discoveries on the prevention and compared with non-asthmatics.
37
This preliminary finding has to be
control of childhood asthma are discussed. confirmed in larger longitudinal studies. Another interesting
development is the measurement of VOCs in exhaled breath by gas
Reliable Asthma Diagnosis in chromatography or electronic nose.
32,38
VOCs in exhaled breath are
Pre-school Children – Is It Possible? produced by lipid peroxidation of cell membranes through reactive
There are large problems with the diagnosis of asthma in young oxygen species of oxidative stress and airway inflammation. This
children. This is a major health problem worldwide as about 40% of all technique has been successfully applied for the early detection of
young children in the population have at least one episode of asthmatic lung cancer in adults.
39
The electronic nose had diagnostic value for
symptoms such as wheezing, coughing and dyspnoea.
14,15,22
Although asthma in adults in a cross-sectional study with 20 patients with
asthmatic symptoms are common in pre-school children, only 30% will asthma and 20 controls. Both young patients with mild asthma and
really persist with wheezing beyond six years of age.
14,15,23
To date, it is not older patients with severe asthma could be distinguished from
possible to discriminate ‘true, persistent asthma’ in pre-school children controls by the electronic nose. Patients with mild and severe asthma
from infants with ‘transient wheezing’ in association with frequent viral would be harder to identify.
38
infections.
24
However, such a distinction is very important for proper
treatment.
25
A diagnosis of transient, viral wheeze at an early stage can It is probable that the use of one or more of these techniques will be
be reassuring for parents. In these children, treatment may be less helpful for an early asthma diagnosis in pre-school children.
40
We
intensive. Inhaled corticosteroids are probably not very effective in this urgently need prospective longitudinal studies of young children with
group and therefore the use of these drugs can be restricted, leading to asthma-like symptoms in which these new techniques of lung
a lower risk of side effects.
25
It may be that leukotriene antagonists function and non-invasive assessment of airway inflammation are
are more effective for the treatment of viral wheeze.
26
An early applied. These cohorts must be followed up until at least six years of
diagnosis of persistent asthma will result in earlier treatment with age and measurements should be applied at regular intervals. Once
inhaled corticosteroids. It may be that early treatment with inhaled the diagnosis at an older age is clear, the predictive value of each of
corticosteroids has a beneficial influence on early airway remodelling in these new methods for a diagnosis of transient wheeze and
pre-school children with asthma.
27
In this way, an early diagnosis will persistent asthma can be determined.
prevent overtreatment of children with transient wheeze and will result
in less undertreatment of children with persistent asthma. What new Prevention of Asthma in Children –
developments do we have for an early diagnosis of asthma? Monofaceted or Multifaceted Interventions?
As environmental factors clearly influence asthma, many studies have
As asthma is a disease characterised by airway inflammation and investigated whether environmental manipulation by reduction
bronchial hyper-reactivity to bronchodilator and bronchoconstrictor of allergen exposure, promotion of breastfeeding and prevention of
stimuli, it is logical to suppose that early measurements of these passive smoking could prevent the development of asthma. We can
phenomena are helpful. Such techniques are, for instance, discriminate between studies in which the effectiveness of one
measurements of airway resistance by the forced oscillation preventative measure was assessed (monofaceted intervention) and
technique or the interrupter technique together with assessment of studies in which several preventative measures were applied together
the response to bronchodilator or constrictor stimuli.
28,29
Although (multifaceted interventions).
41
As asthma is not very easy to prevent,
these techniques are already applied in several centres across the the multifaceted intervention studies may have a higher chance of
world, the precise value for the diagnosis and management of success. However, a drawback of these studies is that in the case of
different wheezing phenotypes has yet to be determined. effectiveness, it is not clear which specific components of the
intervention are effective and which elements are not. The advantage
New non-invasive techniques for assessment of airway inflammation of the mono-intervention studies is that the value of each specific
in children are fractional exhaled nitric oxide (FeNO) in exhaled preventative measure can be assessed.
breath, inflammatory mediators in exhaled breath condensate and
volatile organic compounds (VOCs) in exhaled air.
30–32
In contrast to in A recent meta-analysis compared the effectiveness of monofaceted
older children, the application of FeNO in infants is hampered by the and multifaceted interventions for the primary prevention of asthma
lack of standardisation of the method. Some studies in pre-school in children.
41
Ten prospective birth cohort studies with a total number
16 EUROPEAN RESPIRATORY DISEASE
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