I hear it all the time. “But I wasn't allergic to (nuts, blueberries, watermelon) before!” Sometimes we don't have allergies as children, but they present themselves as we age. I wanted to share some information so patients, hopefully, won't be caught off guard.

Why do we sometimes develop allergies later in life?

Allergies can develop at any stage in our lives. The immune system is dynamic and can react to things we are exposed to, which can include both environmental and food allergens. For example, severe allergic reactions to bee stings and fire ant bites tend to occur later in adult life. Reactions during childhood and young adult years tend to be uneventful.

How does this happen?

These allergies relate to the many moving parts of the immune system – the effectors, mediators and antibodies. When the exposure is right, mediators of the allergic pathway are released, and we experience the reaction, i.e. swelling, redness, itching, cough, wheezing, etc.

What types of allergies can we develop later in life?

We can develop all kinds of allergies later in life. Patients can even develop asthma and allergies after age 40 or as a senior, even though he or she never had breathing difficulties as a young child or adult. I distinctly remember a man in his late-30s who developed severe, anaphylactic reactions after eating tree nuts, requiring ambulance and emergency room visits. This all developed after he grew up eating all kinds of tree nuts!

Can the reverse happen - can you grow out of an allergy?

Yes. In general, allergies tend to get better as we get into our 60s, 70s and beyond. This may be the only thing that gets better with age! You can develop tolerance at various stages. Babies allergic to cow's milk and eggs tend to outgrow these after age 5. Peanut allergies tend to last much longer, but research indicates that 20 percent of people may outgrow the peanut allergy. The skin allergy eczema also gets better after 4 or 5, but tends to be replaced with respiratory allergies.

Is there a specific age that allergies begin to appear?

Allergies tend to develop at an early age. Eczema, or atopic dermatitis, can start in infancy, and so can food allergy. Although egg, peanut and cow's milk allergies are seen in early childhood, development of shellfish allergy tends to occur later.

Can these allergies go away or be cured?

Recently, there is research that is encouraging. There are new methods where patients can be non-allergic for a very long period of time, which is the concept of tolerance. This is demonstrated by patients with bee venom allergy who have completed venom immunotherapy for 3 to 5 years, and they become non-allergic to these bee venoms long after they stop treatment. 

There is also the process of desensitization, where patients are able to tolerate medication that they are allergic to, while they are undergoing this desensitization process, but it is not permanent.

Robin Go, MD, is an allergist with the Medical Group of the Carolinas. He practices at MGC Medical Affiliates – North Grove, located at 1330 Boiling Springs Road, Suite 2500, in Spartanburg. To make an appointment, call 864-585-5433.