The New Lore of Spores
Wakefield, Julie, Environmental Health Perspectives
When it comes to allergies, not all fungi are created equal, according to a study by University of Cincinnati researchers published in the September 2006 issue of Pediatric Allergy and Immunology. Exposure to certain fungal spores can make children more susceptible to developing allergies to mold, pollen, dust mites, pet dander, or foods, the study revealed. On the other hand, exposure to other types of fungal spores may be protective.
Fungal samples were collected in 2003 and 2004 from the homes of 144 infants under age 10 months as part of the five-year Cincinnati Childhood Allergy and Air Pollution Study, supported by the NIEHS. Fungal measurement included long-term air sampling--48 hours, compared to the 5-10 minutes typical of such studies--which improved exposure assessment. The team then analyzed the spore samples, comparing the breakout with allergy symptoms exhibited by the infants (such as sneezing and runny nose) and skin-prick tests for 17 allergens with specific fungal spore counts.
Children who were exposed to higher levels of spores from Basidiomycota (club fungi) and Penicillium/Aspergillus (whose spores are very similar) were more likely to develop multiple allergies, says coauthor Tiina Reponen, a professor in the University of Cincinnati Department of Environmental Health. Those exposed to Basidiomycota were more likely to exhibit allergy symptoms; those exposed to Penicillium/Aspergillus and Alternaria (one of the most common fungi in outdoor air) were more likely to have a positive skin-prick test.
Meanwhile, exposure to Cladosporium (a black mold) had the opposite association, with exposed children testing positive for sensitivity to fewer allergens. This contrasts with the experience of adults, in whom Cladosporium has been associated with greater allergic sensitization.
The researchers did not find any correlation between the total fungi count and allergies. "The [observed] associations would have been missed if the exposure was assessed by using the total [fungal spore] count only," Reponen says. …