Allergies are an extremely common issue throughout the United States and the world. The Allergy and Asthma Foundation of America (AAFA) states, "An estimated 50 million Americans suffer from all types of allergies (1 in 5 Americans), including indoor/outdoor, food & drug, latex, insect, skin and eye allergies." It's a well-known fact that the best way to avoid an allergic reaction is to find out what you're allergic to and then limit your exposure as much as possible. This can be a tricky proposition with seasonal allergies because each part of the United States is home to a wide variety of different weeds, trees and native grasses. To aid in identification, there are eight primary allergy "zones," or allergy regions, in the United States.
The different zones. The continental United States is divided into eight allergy zones, including the Pacific, Mountain, Desert, Plains, Southwest, Great Lakes, South and Northeast. Within each of these zones are distinctly different ecosystems that each house their own assortment of common allergens, as well as unique allergy seasons. Divisions are made based on factors such as average temperature, humidity, precipitation, elevation and so on. Common allergens are fairly similar throughout an allergy zone. Common allergens throughout most of these regions include ragweed, several varieties of grasses, and trees such as oak and cedar.
Using allergy zones. The primary purpose of identifying these different allergy regions is to be able to better focus in on the most likely suspects for your seasonal allergies. You can reference information related to your particular zone to get a basic idea of what's currently spreading pollen in your area, and compare it against the things to which you're normally exposed. Your doctor will likely consult an allergy zone chart to decide which allergens to use in an allergy skin test when determining the source of your allergies. This will help find the most effective treatment to alleviate your symptoms. In addition, if you move from one zone to another and immediately experience a recurrence in seasonal allergies, then you may be allergic to something that's common to both zones.