Asthma does not have to be a burden or cause suffering.

The Global Asthma Report 2014

Prevalence of recurrent wheezing during the first year of life in European and Latin 				American centres.

Figure 1: Prevalence of recurrent wheezing during the first year of life in European and Latin American centres.

Reported severity, medications and other variables in infants with recurrent wheezing during the first year of life.

Figure 2: Reported severity, medications and other variables in infants with recurrent wheezing during the first year of life.

Recurrent wheezing in infants, particularly if they are presenting with frequent and/or severe episodes, should be diagnosed and managed as asthma, unless there is evidence to the contrary.

WHEEZING IN INFANTS

Recurrent wheezing in infants is the most common clinical expression of asthma at that age. It should no longer be considered a benign condition that disappears later in childhood, particularly because many of these infants develop frequent and severe episodes. Early diagnosis and effective management of troublesome recurrent wheezing may decrease the high proportion of infants with recurrent wheezing who have severe episodes as well as visits to the Emergency Department and admissions for wheezing during the first year of life.

International Study on Wheezing in Infants

The largest multi-centre study of wheezing in the first year of life, the International Study on Wheezing in Infants (Estudio Internacional de Sibilancias en Lactantes, EISL), has contributed new information about therapeutic approaches to recurrent wheezing (RW). Data from this cross-sectional study including 30,093 children in 17 centres: 25,030 in 12 centres in Latin America and 5,063 from 5 centres in Europe were published in 2010 (Figure 1). RW in the first year of life, defined as having three or more episodes of wheezing during that time, is common (20%), with a high proportion of these infants suffering from frequent and severe episodes. EISL found that 32.2% of infants with RW have 7 or more episodes (32.3% in Latin America and 31.8% in Europe); 71% reported visits to the Emergency Department (ED) due to wheezing (74% in Latin America and 55% in Europe); and 26.8% reported admission for wheezing during the first year of life (28.4% in Latin America and 14.2% in Europe) (Figure 2). Overall, these figures imply a high burden of health costs for countries and parents in terms of use of health facilities and medications.

The Common Cold

EISL found a strong association between RW during the first year of life (both in affluent and non-affluent countries) and: common viral respiratory illnesses (the symptoms of such illnesses are that of a cold) during the first 3 months of life; attending day-care; wheezing in the first three months of life; male gender; the mother smoking during pregnancy; and family history of asthma or rhinitis. Breast feeding for >3 months and high maternal education showed a protective effect. Thus, avoiding smoking during pregnancy, delaying day-care attendance, breastfeeding babies for at least 3 months, and improving maternal education could be effective strategies for decreasing the prevalence of RW.

There is increasing evidence that having a cold in the first year of life plays an important role in the commencement and/or maintenance of wheezing and asthma in early life. Wheezing illnesses in infants, caused by human rhinovirus and respiratory syncytial virus (RSV) among other things, are robust predictors of subsequent development of asthma, decreased lung function, and increased bronchial responsiveness in school age children. Common cold viruses are by far the most frequent cause of asthma exacerbations at any age.

While there is no consensus on the effectiveness of medical interventions for RW in the first year of life, these infants - particularly if episodes are frequent and/or severe - are frequently treated with asthma medicines, both in hospitals and in primary care. Ninety-one percent of infants with RW used inhaled bronchodilators and 46% used inhaled corticosteroids (ICS) with differences between regions (Figure 2). Evidence-based guidelines also suggest using clinical severity signs (higher frequency and severity of wheezing episodes) as key indicators for starting therapy with ICS in preschool wheeze, with the aim of decreasing the number and severity of wheezing exacerbations. The ways that wheezing is classified in preschool children in clinical and epidemiological studies do not reliably predict the outcome of wheeze over time or the response to ICS treatment. In addition, these classifications of wheezing are difficult to identify in clinical practice and can even change within the first year of life. Thus these classifications of wheeze are not helpful for clinicians when they are deciding treatment for infants with RW.

Management

The effectiveness of ICS in treating children with more severe or persistent symptoms of preschool wheeze in children over 12 months of age is well established. In EISL the high proportion of infants with severe symptoms of RW leading to ED visits, hospital admissions, sleep disturbance, and impaired quality of life, may be partly explained by poor recognition and management of infants with troublesome recurrent asthma symptoms. Contributing factors may include a reluctance to diagnose asthma in young children, a delay in starting proper treatment, prescription of medicines with doubtful efficacy (antileukotrienes) or proven absence of efficacy (antibiotics, cough syrups, antihistamines, among others), or poor education of parents about how to use inhalers and spacers. We suggest outcomes for infants with RW would be improved if the use of ICS could be improved, i.e. a sufficient dose taken over a sufficient time with good adherence.

Conclusion

The EISL data strongly supports the need for efficient, realistic, and easy-to-implement strategies for the education and management of infants with recurrent asthma symptoms, directed at both parents and health care workers, especially in developing countries. Early identification and proper management of infants with recurrent troublesome asthma symptoms is likely to decrease the prevalence of severe episodes, ED visits and hospital admissions, use of inappropriate medications, and other complications. This requires a paradigm shift: health care workers and authorities should no longer consider RW in infancy, especially when frequent and/or severe episodes are present, as a benign condition.

Recommendation

Health professionals in all countries should regard frequent or severe recurrent wheezing in infancy as part of the spectrum of asthma.

Javier Mallol, Luis GarcĂ­a-Marcos, Paul Brand

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