PURPOSE OF THE STUDY.
To further assess a cohort of children examining the relationship between mold exposures at 1 and 7 years of age and asthma at age 7 years.
The sample included 176 children with at least 1 atopic parent followed from birth to age 7 years.
Home assessments, inspections, and floor dust sampling were done at age 1 and 7 years. Clinical examinations were performed at 1, 2, 3, 4, and 7 years of age and included history and skin testing to aeroallergens. At 7 years of age, spirometry pre- and postbronchodilator were performed, and, if negative, a methacholine challenge was undertaken. Children were defined as asthmatic if they had asthma symptoms and objective confirmation of airway reversibility or a positive methacholine challenge. Homes were examined for mold damage, and floor dust samples were collected. A standardized and validated methodology for mold exposure called the Environmental Relative Moldiness Index (ERMI) was used. Children from homes with mold contamination were compared with those from homes without.
Thirty-two percent of the parents of the study children had asthma. Asthma at age 7 years was associated with parental history of asthma (odds ratio [OR] 3.9), allergic sensitization to dust mite (OR 3.3), African American race (OR 3.2), and high ERMI (OR 2.4) by multivariate analysis. Air-conditioning was associated with a decreased risk of asthma (OR 0.3). Mold exposure at age 7 years was not associated with an increased risk of asthma. There was no difference in mold sensitization between groups with high ERMI or low ERMI. The odds of having a home with a high ERMI was associated with African American race (OR 3.0) and negatively associated with air-conditioning use (OR 0.4).
High ERMI value in a home during infancy is associated with an asthma diagnosis at age 7 years.
There are several interesting points from this study, the strength of which lies in the use of a standardized mold assessment technique. As we look for ways to prevent asthma, focusing on exposures in infancy and early childhood are likely to be important. This study identifies mold exposure as one of the risk factors for the development of asthma in at-risk children. It also demonstrates that the effect of exposure does not require allergic sensitization to molds, although the number of molds that were evaluated by skin testing was small and may have missed some sensitization. Regardless, remediation of mold damage in a home during infancy may result in the reduction of asthma, although this needs to be confirmed with prospective studies. This study also supports the association of early dust-mite sensitization and the development of asthma. Dampness in the home is associated with both mold and dust-mite growth; in this study, however, the dust-mite sensitization was not a confounder of the ERMI-asthma relationship, suggesting an independent effect. This study also sheds light on previous studies that have failed to confirm the relationship between mold exposure and asthma. Because the ERMI depends on the quantitative evaluation of mold DNA in floor dust samples, the authors were able to note that visual and olfactory assessment, even by inspectors, missed significant mold problems ∼50% of the time.
- Copyright © 2012 by the American Academy of Pediatrics