NEW YORK (Reuters Health) – Atopic sensitization at an early age and a maternal history of asthma appear to predict the development of childhood asthma, German researchers report.

Dr. Erika von Mutius, from the University Children's Hospital, Munich, and colleagues investigated the pattern of atopic sensitization associated with subsequent asthma in 1314 newborns who participated in the German Multicenter Allergy Study. Of these children, 939 were available for the final follow-up at age 7.

Until the children were 2 years of age, their parents completed six questionnaires that asked about asthma and asthma symptoms. After that questionnaires were completed yearly. There were also yearly tests to determine the specific IgE levels to nine foods and inhalant allergens. When the children reached 7 years of age, they underwent a bronchial histamine challenge.

Atopic children who were asthmatic at 7 years of age had significantly earlier onset of atopic sensitization (39.4% before 1 year of age) compared with atopic children who were not asthmatic at 7 years of age (21%, p = 0.015), the researchers found.

The risk of asthma at age 7 did not increase with early atopic sensitization in the absence of any sensitization to inhalant allergens, according to the report in the November issue of The Journal of Allergy and Clinical Immunology.

The only children who had a significantly increased risk of asthma by age 7 were those who were sensitized to any allergen early and also sensitized to inhalant allergens by age 7 (odds ratio 10.12, compared to never being sensitized).

Even among persistently sensitized children, the risk for asthma was only significantly increased when there was a parental history of asthma or atopy (odds ratio 15.56, compared to never being sensitized), the German team notes, "with the effect being strongest for maternal asthma."

"Our study might provide the missing link between atopy and asthma in childhood, in that an underlying factor pertaining to asthma and maternal transmission may determine both a certain pattern of sensitization and the expression of asthma," Dr. von Mutius and colleagues comment.

"These data support the hypothesis that the development of childhood asthma and atopy run parallel if certain perinatal or hereditary influences prevail, rather than being subsequent stepping stones in a progressive atopic march. Alternatively it may be the asthma that determines the pattern and the level of atopic sensitization," they add.

J Allergy Clin Immunol 2001;108:709-714.