Basidiomycete Skin Test Reactivity Is a Risk Factor for Asthma

Abstract

We determined the relative risk of having asthma that is associated with skin test reactivity to fungi. This was determined for each of two groups of fungi whose members produce major fungal allergens, the basidiomycetes and the conidial fungi (fungi imperfecti). Allergy clinic attendees (n = 701) in seven cities in the United States and five in Europe were skin tested with identical panels of fungal extracts and with extracts routinely used in the local clinic. Asthma diagnoses were self-reported. As expected, the relative risk (RR) of having asthma was significantly greater among subjects having percutaneous reactivity to dust mite (RR = 1.56) and dander (RR = 1.41). The relative risk of having asthma was also significantly (p < 0.001) elevated (RR = 1.37) among subjects reactive to basidiomycete allergen extracts. In comparison, the relative risk of having asthma among subjects reactive to conidial fungi was only 1.15 and was significant only at p = 0.107. The prevalence of basidiomycete sensitization was previously shown to be comparable to that of conidial fungi, and is known to cause asthmatic reactions under controlled exposures. This study demonstrates that sensitization to basidiomycetes is a risk factor for asthma in populations of clinic attendees.