Infants exposed to specific molds have higher asthma risk

Published Online: July 12, 2012

Previous case-control studies have demonstrated that many environmental exposures can trigger asthma symptoms in people with asthma. Exposure to mold has been linked to worsening of asthma symptoms, but the relevant mold species and their concentrations are unknown.

A team of physicians and scientists from the University of Cincinnati, EPA, and Cincinnati Children’s Hospital performed a decade long study assessing the children’s health and exposure to indoor molds and allergens. Reponen et al. report these findings in an upcoming issue of The Journal of Allergy and Clinical Immunology (JACI).
The nearly 300 infants recruited for this study were born to parents who were skin-prick test positive (SPT+) to at least one of 15 aeroallergens. The child’s atopic status to 15 aeroallergens, milk and egg, and respiratory health was monitored yearly at ages 1, 2, 3, 4, and 7. Clinical exams and in person health histories tracked the child’s progression from wheezers to a final objective diagnosis of asthma. This asthma diagnosis was based on symptoms, pulmonary function testing, bronchial hyperresponsiveness, and methacholine challenge testing at age seven. In the home, allergens from cockroach, dog, cat, and house dust mite were measured at age one and at age seven. The concentrations of 36 common molds were quantified using a DNA-based analysis method. Twenty-six of the 36 molds are typically found growing in water-damaged homes and the other ten migrate indoors from outside.  

By age 7, 24% of the children were asthmatic. The majority of the asthmatic children were skin-prick test positive, African-American, from low income families (less than $20 K/year) and had an asthmatic parent. Among the monitored indoor exposures, only mold exposure in infancy was a risk factor for asthma at age seven. Of the 36 molds quantified, three molds, Aspergillus ochraceus, Aspergillus unguis, and Penicillium variabile from the group of molds typically found growing in water-damaged homes were linked to asthma development. None of the outdoor molds were linked to asthma.  

Remediation of infants’ homes for water damage and mold may mitigate some cases of asthma. Therapeutics for asthma may be more efficient if targeted towards specific mold species.

The Journal of Allergy and Clinical Immunology (JACI) is the official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.

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