The Role of Inhaled Corticosteroids in Management of Asthma in Infants and Preschoolers

Jose A. Castro-Rodriguez; Søren Pedersen

Disclosures

Curr Opin Pulm Med. 2013;19(1):54-59. 

In This Article

Abstract and Introduction

Abstract

Purpose of review This review analyses published data on the treatment of wheezing in infants and preschoolers with inhaled corticosteroids (ICS), including the effect in subgroups of patients such as 'multiple trigger wheeze' and 'episodic viral wheeze'.

Recent findings Therapy with ICS at daily doses of 100–200 μg results in significant clinical improvements in several outcomes in preschoolers and infants suspected of having asthma (multiple trigger wheeze). Such treatment is normally considered well tolerated. Although not well studied, higher daily doses may be associated with measurable effects on growth, which are not cumulative with continued treatment. In children who only wheeze in association with viral infections (episodic viral wheeze), preemptive treatment with high doses of ICS has demonstrated significant clinical effects on several outcomes, whereas lower doses seem to have little effect. Intermittent use of high doses of ICS has been associated with significant reductions in height and weight gain over 1 year.

Summary The review illustrates the complexity of treating wheezing in infants and preschoolers and interpreting the study results. It emphasizes the need for more studies in clinical subgroups, more long-term studies and dose–response studies to assess the optimal doses and safety of intermittent as well as regular ICS treatment.

Introduction

Even though almost 80% of asthmatic patients start having symptoms during the first 5 years of life,[1] the diagnosis of asthma in infants and preschoolers is more challenging than in older children and adults. Recurrent wheezing is frequently associated with upper respiratory tract infections, which in this age group occur approximately six to eight times per year.[2] Preschool wheezing is a highly heterogeneous condition, and several different phenotypes have been proposed.[3–7] However, individual phenotype allocation is very difficult in a 'real-life' clinical situation.[8] Therefore, a symptom-based classification that divides wheezing illness in preschool children into episodic (viral) wheeze (EVW) and multiple-trigger wheeze (MTW) phenotypes has been proposed.[9] This classification has not been validated and markedly criticized for several reasons.[10–12]

Several studies in older children with asthma have found that the level of asthma control is overestimated and the impact of the disease upon the daily life of the child underestimated, mainly because it is difficult to correctly assess symptoms and the extent to which the child has adapted his or her lifestyle to avoid symptoms. Most parents (and many physicians) believe that as long as the child is not suffering from audible wheeze there is no problem, but the presence or absence of wheeze is a crude indicator of whether a child has clinically important airway obstruction because audible wheeze may not be present while the lung functions are markedly reduced.[13]

On the other hand, accurate identification of symptomatic preschoolers with wheezing who are at risk for developing asthma later in life might allow for better targeting of secondary preventive actions and therapeutic strategies.[14] A number of asthma predictive scores have been developed with this aim.[15–17] The most widely used is the asthma predictive index (API).[15] The API has been adopted in some asthma guidelines.[18,19] The best parameter for determining the usefulness is the likelihood ratio, which in the case of the API is 7.3. This means that using the API in real life would increase the probability (posttest) of a correct prediction of asthma later in life by two to four times, making the API a useful tool for predicting asthma in most clinical situations.[20]

Mentioning the risk of 'asthma' in infants/preschoolers with recurrent wheezing and a positive API may make parents more likely to accept and adhere to a prolonged treatment period. At present, the API has not been convincingly shown to be useful in predicting response to therapy. There is a certain amount of overlap between the various phenotypes. Thus, intermittent episodic wheezing of any severity may represent unrecognized, uncontrolled asthma, an isolated viral-induced wheezing episode or an episode of seasonal or allergen-induced asthma. So, decisions of not treating anybody in one group would lead to undertreatment of a certain number of children, whereas treating everybody would lead to marked overtreatment.

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