Whatever the season, the runny nose, itchy eyes and sneezing of an allergy are unwelcome visitors. During the spring and summer, grass pollens are circulating in the air. In the fall months, the offender is more likely to be weed pollens such as ragweed or sage brush. In Southern states, various trees release pollens during the winter months.
Outdoor molds can be a problem any time it's damp and rainy.
At least 26 million Americans suffer from chronic seasonal allergies, according to the National Center for Health Statistics. One solution is to stay indoors during the pollen season, but this is not always possible or desirable. And people allergic to pollens are often sensitive as well to dustmites, animal dander and molds that lurkindoors at any time of year. Allergies have always been a problem, but their incidence has risen dramatically in recent years, especially in developed countries. Studies have shown that people living in rural Africa, India and Russia have fewer allergies than those living in England, New Zealand and Australia.