A mixture is prepared that contains the allergens identified in your allergy tests. The mixture is injected into your skin in tiny but increasing amounts over the course of many months. The injections eventually desensitize you to the allergens. Usually, after 4 to 6 months of allergy shots, people begin to have relief from their allergies. However, you may need to continue the shots for 2 to 3 years or longer.
Allergies last different amounts of time for each person.
Allergies can develop at any age. Children with seasonal allergies may continue to have allergies as they grow older or the allergies may go away over time. If you start having allergies as an adult, you will probably continue to have them. However, the allergies may stop if you move to an area where the substances causing your allergies are not present. There are no known methods or techniques for preventing allergies.