NEW YORK (Reuters Health) – In children at heightened risk for atopy, common childhood immunization is not associated with an increased risk of more severe eczema or allergic sensitization, according to findings published in the current issue of the journal Allergy.

“Atopic diseases are among the commonest chronic conditions in childhood,” Dr. Christoph Gruber, of Universitatsmedizin Berlin, Germany, and colleagues write. “Parents of children at heightened risk for atopy are frequently concerned about the effect of immunization in infancy.”

The researchers examined the effect of immunization in the first year of life in 2184 infants between the ages of 1 and 2 years with active atopic dermatitis and a family history of allergy. The subjects were screened in 94 centers from 12 countries. Based on elevated total IgE and/or allergic sensitization, 65.1% of the children were atopic.

Immunization coverage and timing varied widely by country, as did the proportion of children immunized and with what vaccines. The mean age at first immunization was 1.1 months.

No association was observed between immunization with any particular vaccine and an increased risk of allergic sensitization or eczema severity.

On the other hand, there was an inverse association between varicella immunization and elevated total IgE (adjusted odds ratio 0.27, p = 0.028) and eczema severity (adjusted OR 0.34, p = 0.036), and between pertussis immunization and eczema severity (adjusted OR 0.30, p = 0.027).

Furthermore, the cumulative vaccine dose was compared “between infants already afflicted from atopic dermatitis at a given age and infants who were still free from atopic dermatitis,” Dr. Gruber and colleagues explain. “There was no significant difference in the cumulative immunization dose between both the groups.”

The team concludes, “Parents of atopic children should be encouraged to fully immunize their children.”

Allergy 2008;63:1464-1472.