Editors' ChoiceAsthma

MOLDing Childhood Asthma

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Science Translational Medicine  12 Sep 2012:
Vol. 4, Issue 151, pp. 151ec167
DOI: 10.1126/scitranslmed.3003904

Molds are ubiquitous in our environment. Some types of molds are valuable—for example, in the synthesis of antibiotics or to help make cheese and fertilize gardens. However, when it comes to asthma, which affects some 22 million U.S. adults and children, exposure to certain mold species has been linked to life-threatening asthma exacerbations. Recent research has supported the role of mold in triggering the development of asthma. However, specific mold species and timing and durations of exposure that may be contributory to the pathogenesis of asthma are unknown.

Reponen et al. further investigated the relationship of early exposure to specific molds on the development of childhood asthma. The authors hypothesized that specific mold exposures are associated with childhood asthma development. Dust samples were collected from homes of 289 infants when they were ~8 months of age and analyzed for concentrations of 36 molds that are part of the Environmental Relative Moldiness Index (ERMI). For infants to be eligible for the study, at least one of the parents had to be classified as atopic. Children were evaluated at age 7 years for asthma based on clinical symptoms and spirometric testing, an objective measure of lung function. The children also underwent skin prick test to aeroallergens and mold. Asthma was diagnosed in 24% of the children examined. Mold exposure in infants’ homes correlated with a child having asthma at age 7 years: A 10-unit increase in the ERMI scale raised the risk of asthma by 80%. Indeed, infant exposure to three specific mold species usually found in water-damaged homes was significantly associated with asthma development at age 7 years.

Although the findings of this study are intriguing, they do not yet prove that three specific molds can cause asthma. However, they may provide a starting point for targeted laboratory studies. Limitations of this study include small sample size and evaluation of a fraction of the total existent molds in the samples. Future prospective studies may address these limitations. In the meantime, expectant parents with a family history of asthma or atopy may want to consider correcting any water or mold problems in the home before their baby’s arrival.

T. Reponen et al. Infant origins of childhood asthma associated with specific molds. J. Allergy Clin. Immunol. 130, 639–644 (2012). [PubMed]

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