Early-onset hay fever in Israeli children

In order to investigate the influence of climate and vegetation on the age of onset and clinical picture of hay fever (HF), we examined 116 children with typical HF living in a single climatic area: fifty-four were from rural farming settlements and sixty-two from towns and cities. Overall age of onset was low; 72% of rural children developed HF between the ages of 2 years and 4 years compared to only 24% of urban children (P less than 0.005). At the same time, 57% of rural children had positive skin tests to more than three pollen extracts out of nineteen allergens tested, compared to 19% of urban children (P less than 0.005). There were no significant differences between the rural and urban groups with regard to the incidence of asthma as part of their HF, nor were there differences in total IgE levels. The results of this study suggest that Israeli children develop hay fever earlier than generally reported in the literature, and that this is most marked in the rural areas. This can be explained by their specific environment, which consists of a basically dry, desert-like climate where lawns, crops and trees are extensively irrigated, leading to the dissemination into the environment of large amounts of pollen grains, which are not washed away because of the lack of rain.