Prevalence varied when subsets of non-allergic (5%), non-pollen-allergic (10%), and pollen-allergic (31%) subjects were considered.
Prevalence further increased in subsets with multiple pollen sensitization (71%), and with a previous pollen immunotherapy course (46%), whereas minor differences were found in gender and age distribution.
Almost all the allergenic extracts recorded negative in the skin test gave a positive IgE test in vitro. A higher correlation was found mainly with plant-derived allergenic extracts, whereas a lower one was recorded with mites and fungi. Horseradish peroxidase was the only glycoprotein capable of exerting a positive skin test in 21% of the subjects with IgE to cross-reacting carbohydrate determinants, 80% of them having IgE to the HRP molecule. IgE to cross-reacting carbohydrate determinants are common among the allergic population and the binding to skin test negative allergenic extracts further confirms their poor biological activity. #The binding of isaac unblocked noodle skin
