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Allergies can find you at any age. In fact, they can come and go at will, whether you’re 7 or 77. This means you can live decades of your life and suddenly become allergic to something as an adult, a condition known as adult-onset allergies.

Over the course of your lifetime, you can develop:

• Environmental allergies from dust, mold, or pet dander.
• Food allergies, especially to shellfish, peanuts, and tree nuts, which are among the most common.
• Insect sting allergies, particularly from bees.
• Medication allergies, notably to antibiotics such as penicillin.
• Seasonal allergies to tree pollen or grass, for example.

So what steps can you take toward managing allergies? And what helps with allergies?

Let’s review the science and then look at treatments and strategies you might try.

What Is An Allergy?

An allergy is an immune system reaction.

Your immune system protects you from invaders. But sometimes, for reasons that aren’t always clear, it misidentifies something harmless as something harmful. When this happens, your body releases chemicals called histamines.

That’s where the symptoms come from, which can include:

• Sneezing.
• Runny nose.
• Watery eyes.
• Itchy nose, eyes, throat, and ears.
• Hives or other skin irritation.
• Nausea or other digestive problems.

Seasonal allergies are the most common among adults, affecting about 25% of adults, according to the Centers for Disease Control and Prevention. Seasonal allergies are sometimes called “hay fever.” Hay fever symptoms (runny nose, watery eyes, congestion) range from mildly annoying to miserable.

Other types of allergies (usually food or insect stings) can cause a life-threatening condition called anaphylaxis. This means your throat starts to close up. If this happens, you need an emergency shot of epinephrine (EpiPen).

Food allergies are more common in children, but adults can develop them.

What causes allergies?

Allergy and immunology experts have theories, but it’s still partly a mystery. If you recently moved to a new area, you may discover you’re allergic to the tree pollen in that part of the country.

Taking antibiotics or having an illness might trigger certain allergies. Pregnancy can also trigger allergies (and, interestingly enough, make them go away).

What Medications Can Help Manage Adult-Onset Allergies?

You might start with an over-the-counter allergy medicine for seasonal and environmental allergies, like pollen or dust. These include:

• Antihistamines. These medicines help block the effects of the histamines reducing the symptoms. They include cetirizine (Zyrtec), desloratadine (Clarinex), fexofenadine (Allegra), levocetirizine (Xyzal), and loratadine (Claritin).
• Decongestants. These medicines help dry a runny nose, and you can take them along with other medicines.
• Nasal corticosteroid sprays. These include products like fluticasone propionate (Flonase) and mometasone (Nasonex). They tend to work well to relieve allergy symptoms.

What About Allergy Shots or Oral Immunotherapy for Adults?

If other medicines haven’t worked, you might consider allergen immunotherapy or allergy shots.

This therapy exposes you to a little bit of the allergen, increasing the dose with each shot. Your body slowly gets used to the allergen, which makes your symptoms less severe.

People usually get allergy shots for allergies like pollen, dust mites, or insects. They can also help with asthma.

Your doctor will determine the course of your shots, but they usually start with weekly shots for about six months. After that, you’ll enter the “maintenance” phase. At that point, you’ll get shots monthly, usually for three to five years.

For food allergies (like peanuts and tree nuts), doctors offer oral immunotherapy (OIT).

Instead of getting a shot, you eat a small dose of allergen every day. Then, you slowly increase the amount you eat, usually over six months. When you’re in the maintenance phase, you may eat the food weekly.

OIT has mostly been a treatment for children and adolescents. However, some doctors and researchers are now including adults and finding some success.

Can Lifestyle Changes Help My Allergies?

The classic treatment for allergies is avoidance. But it’s harder to avoid allergens like dust, pollen, and mold. Some things you can do that might help:

• Consider getting rid of rugs and carpets where possible.
• Don’t have the windows open when pollen counts are high.
• Run a dehumidifier to reduce the moisture in your house (moisture can make mold worse).
• Use air filters and change your furnace filter regularly.
• Vacuum frequently.

Should I See an Allergist?

An allergist can tell you exactly what you’re allergic to (and how allergic you are) through testing. They usually combine skin and blood testing.

Allergists can also prescribe medicines that aren’t available over the counter.

They can also help you understand your allergies and create a plan for dealing with them.

Seeing an allergist is a good idea if you:

• Find that your allergies are interfering with your day-to-day activities.
• Have had a serious allergic reaction, like anaphylaxis.
• Have hay-fever-like allergy symptoms (sneezing, itching, congestion) more months of the year than not.
• Have trouble controlling your allergy symptoms with over-the-counter medicines.
• Keep getting sinus infections.

Navigating Allergies and Finding Support

Your allergist can help you decide which treatments are right for you. But if your new allergy is severe or even life-threatening, you may need more support.

If you have food allergies, consider a food allergy support group. Food Allergy Research & Education (FARE) can help you find one.

Food Allergy & Anaphylaxis Connection Team (FAACT) also has good resources for adults.

Other tips to help navigate food allergies:

• Always keep allergen-free snacks with you, especially when traveling.
• Communicate ahead of time with friends or family if they are preparing food for you.
• Consider ordering a medical ID bracelet that lists your allergies.
• Make sure you know how to use the EpiPen prescribed to you.
• Read all labels — all the time.

UPMC has a long tradition in immunology research and training. The multidisciplinary team in UPMC’s Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine collaborates both inside and outside of UPMC’s Comprehensive Lung Center. The division treats:

• Allergies.
• Deficiencies of the immune system.
• Various diseases associated with allergic and immunologic disorders.

If you have questions, call 412-648-6161 or request an appointment online.

Editor's Note: This article was originally published on January 16, 2025, and was last reviewed on December 18, 2025.