Can You Actually Develop Allergies Later In Life?

Allergies occur when the immune system reacts to a foreign substance or food that doesn't cause a reaction in most people (via Mayo Clinic). Common allergens include pollen, ragweed, pet dander, dust mites, bee venom, shellfish, nuts, and dairy. Symptoms of allergies will vary by cause, but can include sneezing; itchy or watery eyes; a runny nose; hives; swelling of the lips, tongue, throat, or face; rashes; itchy skin; and anaphylaxis.

Most people with allergies develop them at a young age (via Healthline). In fact, 1 in 5 children have some kind of allergy or asthma. A lot of people outgrow allergies in their 20s or 30s, especially food allergies like milk, eggs, and grains. However, it is possible to develop allergies at any point in life, and to become allergic to something you hadn't been allergic to before.

Doctors aren't sure why some people get allergies later in life. One possible reason is moving to a new geographic location (via Mayo Clinic). If you lived in one area for all of your life that has certain plants and trees and then moved to another place with a different mix of vegetation, you may develop an allergy to those new plants. Still, sometimes a person can develop new allergies for no apparent reason.

How allergies are diagnosed

If you are experiencing symptoms of allergies, it may be worthwhile to get allergy testing. This will help determine what you are allergic to, or, if in fact, you do have allergies. First, you'll want to make an appointment with an allergist or immunologist (via Cleveland Clinic). The most common type of allergy test is a skin prick test. This involves applying an extract of allergen to your skin and evaluating the reaction for allergies. An intradermal skin test is similar to a skin test, but is more sensitive and the allergen is injected under the skin. Sometimes doctors will try a patch test, in which they will place a small amount of allergens on the skin and then cover the area with a bandage to see if an allergic reaction occurs. This may be done if an allergy is suspected with a delayed allergic reaction. If a skin test cannot be used, a blood test for allergies is available.

When it comes to food allergies, doctors may have you try an elimination diet. This involves eliminating or isolating specific food items from your diet to see if symptoms change. There's also the challenge test, in which a person swallows a small amount of food or medication that is suspected to cause allergies. Since there's risk of a life-threatening reaction, this is always done with consent and under medical supervision, so a healthcare provider can provide immediate treatment if needed.