Pollen Allergy in Children (ll): The Significance of Tree Pollen As a Causative Allergen in Children with Allergic Diseases

ABSTRACT

PURPOSE: The positive rates of allergy skin test of pollens are relatively higher in children in Suwon compared to other areas in Korea. To evaluate the significance of tree pollen as a causative allergen, we undertook this study. METHODS: In 252 children with asthma, scratch tests were done with 72 extracts, including 9 tree pollen. Antigen specific serum IgE antibodies were measured by radioimmunoassay. In 2 children, birch-bronchial challenges were performed. RESULTS: By allergic skin tests, 231 of 252 children showed positive skin reactions to more than 1 antigen, and 102 (44.2%) showed positive reactions to tree pollen extracts. Twenty-five (24.5%) were house dust mites non-sensitive, tree pollen sensitive children. The skin test positivity to individual antigens are as follows D. pteronyssinus (72.7%), D. farinae (68.4%), hazel (53%), willow (53%), birch (19.9%), oak (19.5%), beech (17.3%), alder (10.4%), ash (8.7%) and elm (7.4%). The degree of skin reaction to tree pollen was relatively weaker than those of house dust mites. The positive concordance rates between skin tests and specific IgE reactions to D. pteronyssinus, D. farinae and tree pollens were 94.4%, 77.3% and 64.1%, respectively. Seven out of 25 mite non-sensitive children had seasonal pollinosis and 2 children experienced early asthmatic responses due to birch-bronchial challenge tests. CONCLUSION: Up to 44.2% of children with respiratory allergy showed positive reactions to tree pollen extracts and 24.5% of them were house dust mites non-sensitive cases. Therefore, tree pollen should be investigated as a causative allergen, regardless of a patient's age.