Minority of Children With Atopic Eczema Develop Asthma
NEW YORK (Reuters Health) Oct 12 - Contrary to common belief, only a minority of infants and young children with atopic eczema go on to develop asthma, according to a report in the September Journal of Allergy and Clinical Immunology.
Eczema and asthma are complex disorders brought about by an interaction of numerous genetic and environmental factors, only few of which are known, Dr. Paul L. P. Brand from Princess Amalia Children's Clinic, Zwolle in the Netherlands told Reuters Health. A simple linear progression from eczema to asthma is "an oversimplification," he added.
Dr. Brand and colleagues conducted a systematic review to assess the risk of developing asthma in children with atopic eczema during the first 4 years of life. They examined 13 prospective cohort studies.
In four birth cohort studies, atopic eczema was associated with a statistically insignificant 2.14-fold increase in the risk of developing asthma, the authors report.
In nine eczema cohort studies, the weighted prevalence of asthma at follow-up was 29.5% for the mixed group of inpatients and outpatients.
These estimates "are considerably lower than the risk estimates provided in many review articles and medical textbooks," the investigators say. "Our systematic review shows that on average, only 1 in 3 young children with atopic eczema develops asthma at the age of 6 years or older."
"The relationship between asthma and atopic eczema seems complex, and both genetic and clinical findings suggest that it is not one of simple progression of atopic eczema into asthma as popularly described in the atopic march concept," the researchers conclude.
Dr. Brand added that his group is "discussing the possibilities of conducting a large cohort study following up children with eczema until adult age."
J Allergy Clin Immunol 2007;120:565-569.