Deuteromycete aerobiology and skin-reactivity patterns: A two year concurrent study in Corpus Christi, Texas, USA

Baseline aerobiologic data of known and potentially allergenic deuteromycetes in Corpus Christi, Texas, USA, are presented concurrent with analyses of patient skin-reactivity (November 1987-October 1988 & November 1988-October 1989). Species representations of deuteromycete spores and their relative abundance were similar for two years. Three distinct groupings were discerned: Cladosporium (representing 80% of total spores) showed weekly averages predominantly in 1000-5000/m³ range; Alternaria (7.8%), Aspergillus/Penicillium (5.3%) and Torula (0.8%) at primarily 500-1000/m³ level; and Epicoccum (1.3%), Fusarium (1.3%), Nigrospora (1.3%), Stemphylium (0.6%), Drechslera (0.5%), Curvularia (0.2%), Pithomyces (0.1%) and other minor genera, mostly in 100-500/m³ range. Spore-bursts were recorded for all deuteromycetes with extreme spore-burst capture most prevalent among sporadic spores (e.g., Curvularia and Torula). Two-thirds of the 602 atopic persons were skin-test positive to 1 or more of the 10 deuteromycete extracts. Alternaria, Cladosporium, Curvularia and Epicoccum elicited highest skin-reactivities (31.2% to 32.1%), despite wide disparity in spore concentration. Twenty-seven percent of patients were positive to Nigrospora and Stemphylium. Significant paired skin-reactivities of several deuteromycetes were detected using Kendall's Tau-β correlation coefficient. Factor Analysis of skin rectivity revealed two groupings, suggestive of cross-reactivity: Factor Group 1 consisted of Curvularia, Epicoccum, Fusarium, Cladosporium, Alternaria and Aspergillus extracts (Factor Loadings 0.56 to 0.86); Factor Group 2 included Helminthosporium, Nigrospora, Penicillium, Alternaria and Stemphylium extracts (0.45 to 0.76). High inherent allergenicity, strong cross-reactivities of shared or closely related allergens, and micro-environmental factors such as exposure to uniquely high spore concentrations or bursts, may help explain the major dissimilarities between spore capture and patient sensitization in Corpus Christi.