Mold, water damage linked to wheezing in infants

NEW YORK (Reuters Health) - The results of a new study suggest that mold and dampness in homes are significant risk factors for recurrent wheezing in infants at high risk of allergic disorders, whereas house dust mite exposure does not significantly increase the risk.

"In most studies that investigate the association of mold or water damage and respiratory disorders in infants, the analysis is not adjusted for exposure to house dust mite, which is also a known cause of respiratory illnesses," Dr. Tiina Reponen, of the University of Cincinnati, Ohio, and colleagues write in the latest issue of the Annals of Allergy, Asthma, and Immunology.

As part of a study in infants of parents with allergies, the researchers performed on-site home visits when the infants were 8 months old to assess visible mold or water damage and levels of house dust mite allergen.

The 640 infants in the study had a first clinic visit at an average age of 13 months. During this visit, the team took medical histories, including parent-reported wheezing episodes, and performed skin prick tests for exposure to food allergens, substances known to trigger allergic responses in susceptible individuals, and 15 common airborne allergens.

The team found that 51 percent of homes had minor water damage or mold problems and 5 percent had major conditions. Only 16 percent of homes had house dust mite allergen levels high enough to cause an allergic response.

House dust mite exposure was not a significant risk factor for wheezing, the investigators report.

On the other hand, the risk of recurrent wheezing was increased nearly two-fold in infants who lived in homes with major mold or water damage.

The risk was five times greater in infants with reactions to food or airborne allergens and six times greater in infants with reactions to airborne allergens.

However, neither mold nor water damage correlated with reactions to mold or airborne allergens, Reponen and colleagues report.

"It remains to be determined how environmental exposure affects the development of sensitization and wheezing," they conclude, "and what relationship exists between the early onset of wheezing and the development of asthma in these infants as they age."

SOURCE: Annals of Allergy, Asthma, and Immunology, October 2006.