By John Hunt, MD
Pediatric Allergist/Immunologist and Pediatric Pulmonologist
Seasonal allergies result from pollen exposure in people who have developed allergic sensitivities to the pollens. In general, trees and grasses that pollinate in the springtime present problems. In the middle latitudes, trees begin pollinating in late February, with various species continuing to pollinate through May. Grasses pollinate in May and June. There are substantial geographic variations in this pattern, however.