Neonatal birch-pollen contact and subsequent allergy to birch pollen.
It is shown by regression analysis that the risk of immediate hypersensitivity to birch pollen, as measured by a skin test, is positively correlated with the quantity of birch male flowers and the number of non-rainy days in the first birch flowering season (May) met in infancy. The risk is also dependent on the month of birth, with maximal risk associated with birth in February--April. The results suggest that early pollen contacts, particularly during the first 6 months of life, increase the risk of pollen allergy for a period of 20 years. We estimate that elimination of early birch pollen contacts could have reduced the prevalence of immediate hypersensitivity to birch by 28% in our age gorup 0--19 years.
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000209:etiology*; D006969:Hypersensitivity, Immediate / Q000209:etiology; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008433:Mathematics; D011058:Pollen; D012306:Risk; D012621:Seasons; D012882:Skin Tests; D014197:Trees