Dictionary of Allergies .. Asthma in infancy

In many ways, pediatric asthma differs from adult asthma, including childhood-onset adult asthma. Despite many advances in our understanding of the disease, the natural history of asthma is not well defined, especially in different subsets of patients. For many with allergic asthma the disease has its origins in early childhood, associated with early sensitization to aeroallergens and exposure to repeated viral infections.

These early life exposures, coupled with genetically determined susceptibility, have a major impact on the natural history of the disease. A number of risk factors during the critical early stages in the initiation of asthma have been associated with subsequent outcomes. In addition, protective factors linked to early life experiences have also been delineated which may impact the development of atopy and asthma and reduce the prevalence of these diseases.

Cumulatively, the data highlight the critical nature of this early period in which immune/inflammatory responses in the lung are initiated and serve to maintain the disease in subsequent years[1]. Risk factors: A number of epidemiological studies have defined risk factors for the development of asthma in younger children. A parental history of asthma and atopic disorders is a clear risk factor for boys but not for girls. Eczema in the first year is a risk factor for both sexes. Wheeze in the first year of life and in particular acute viral bronchiolitis is certainly a risk factor, probably again mainly for boys. Prolonged breast feeding, at least for the majority of infants, does not seem to be particularly protective. There are no well-defined risk factors for severe asthma in infancy. Age of onset is not a risk factor for the continuation of asthma into later childhood and adult life. Eczema, however, is and so are frequent episodes of wheeze or periods of continuous wheeze in the early years of life. There are no reported studies of the efficacy of therapy in altering this natural history.

References

1. Gelfand EW. Pediatric asthma: a different disease. Proc Am Thorac Soc. 2009 May 1;6(3):278-82

2. Phelan, P.D.: Asthma in infancy: Risk factors. Triangle Suppl. 1., vol. 26, 19-24 (1987).