Differential effects of outdoor versus indoor fungal spores on asthma morbidity in inner-city children.
BACKGROUND
Although sensitization to fungal allergens is prevalent in inner-city children with asthma, the relationship between fungal exposure and morbidity is poorly understood.


OBJECTIVE
We examined relationships between fungal sensitization, exposure, and asthma morbidity in inner-city children.


METHODS
Participants were 5 to 11 years old and enrolled in the Inner-City Asthma Study. This report includes the subset of children with at least 1 positive skin test (PST) response to a fungal allergen extract; for these children, indoor and outdoor airborne culturable fungi levels were measured at baseline and throughout the 2-year study. Asthma morbidity measures were collected prospectively. The primary outcome was symptom days per 2 weeks.


RESULTS
At baseline, children with a PST response to a fungal allergen extract had significantly more symptom days compared with those without a PST response to any fungal allergen extract (6.3 vs 5.7 days per 2 weeks, P = .04). During the study, increases in total fungal exposure and indoor Penicillium species exposure were associated with increases in symptom days and asthma-related unscheduled visits. Indoor exposures to total fungi and to Penicillium species were associated with significant increases in unscheduled visits, even after controlling for outdoor fungal levels. Adverse effects associated with exposure to a specific fungus were stronger among children with PST responses to that fungal allergen extract compared with those seen in children with negative skin test responses.


CONCLUSIONS
Outdoor fungal exposure is primarily associated with increased asthma symptoms and increased risk of exacerbations in this population.
Pongracic
Jacqueline A
JA
Children's Memorial Hospital, Northwestern University Feinberg School of Medicine, Chicago, Ill, USA. j-pongracic@northwestern.edu
O'Connor
George T
GT
Muilenberg
Michael L
ML
Vaughn
Ben
B
Gold
Diane R
DR
Kattan
Meyer
M
Morgan
Wayne J
WJ
Gruchalla
Rebecca S
RS
Smartt
Ernestine
E
Mitchell
Herman E
HE
D016902:Air Pollution, Indoor / Q000009:adverse effects*; D000485:Allergens / Q000276:immunology*; D001249:Asthma / Q000453:epidemiology* / Q000209:etiology / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D005658:Fungi / Q000276:immunology; D006801:Humans; D008297:Male; D009017:Morbidity; D015337:Multicenter Studies as Topic; D016032:Randomized Controlled Trials as Topic; D013172:Spores, Fungal / Q000276:immunology*; D014504:Urban Health; D014505:Urban Population
D000485:Allergens