Pollen and mould allergy in Southern Sardinia (Italy): Comparison of skin-test frequencies and air sampling data

A study was carried out to investigate the influence of atmospheric pollen and fungi in determining allergic diseases by comparing the frequency of skin reactions to air sampling data over a 6-year period. 48% of our population reacted to at least one of the pollen and fungal extracts used. Among pollen, Gramineae gave the most frequent positive reactions, followed by Parietaria, Olea and Compositae. The most common positive skin tests in fungus sensitive patients were by extracts of Alternaria, Cladosporium, Aspergillus and Candida. As for the aerobiological survey, the general trend of pollen and molds was similar during the sampling period. The annual pollen catch did not show remarkable differences during the years sampled, whereas the total fungal spore count was highest in 1988 and 1990. A comparison between aerobiological and clinical data revealed a good degree of concordance between total pollen counts and positive skin test frequencies for Urticaceae, Gramineae and Oleaceae but not for Compositae (high positive skin reactions and very low counts) and Cupressaceae (high counts and few skin reactions). A less marked correlation has been found between fungal spore counts and positive skin-test Frequencies as compared to pollen. Spores such as Cladosporium, which are present in large number in the air, appear to be less sensitizing, while certain spore types (e.g. Alternaria), seem to be able to sensitize patients in spite of their low atmospheric concentrations.