Background: Glucan is a component of the fungal cell wall that is used as a marker of fungal exposure. Little is known about indoor glucan, atopy, and asthma exacerbations among children living in tropical environments such as Puerto Rico. Our objective was to examine whether glucan exposure is associated with degree of atopy or visits to the emergency department (ED)/urgent care for asthma in Puerto Rican children.
Methods: This was a cross-sectional study of 317 children aged 6 to 14 years with (cases, n = 160) and without (control subjects, n = 157) asthma in San Juan, Puerto Rico. Our primary outcomes were the number of positive skin tests to allergens (range, 0-15) and (in cases only) having had at least one visit to the ED/urgent care for asthma in the prior year. Levels of glucan, endotoxin, peptidoglycan, and five allergens (Der p 1, Bla g 2, Fel d 1, Can f 1, and Mus m 1) were measured in samples of house dust. Linear or logistic regression was used for the multivariate analysis.
Measurements and main results: In a multivariate analysis adjusting for case-control status, mouse allergen, and other covariates, children exposed to glucan levels in the second and third quartiles had approximately two more positive skin tests than those in the lowest quartile (P < 0.01 in both instances). Among children with asthma, exposure to the highest quartile of glucan was associated with nearly ninefold greater odds of one or more visits to the ED/urgent care for asthma (95% confidence interval for adjusted odds ratio, 2.7-28.4; P < 0.001).
Conclusions: Our results suggest that indoor fungal exposure leads to an increased degree of atopy and visits to the ED/urgent care for asthma in Puerto Rican children.
Keywords: Puerto Ricans; asthma attacks; children; fungi.