Mold and childhood asthma

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.