Can You Develop Allergies as an Adult?

Aging can bring a lot of changes to your body — including allergies that seemingly develop overnight. So, don’t be surprised if spring pollen suddenly sets off sneezing fits after never being an issue before.

Why does this happen? We asked allergists Lily Pien, MD, and Dylan Timberlake, MD, to explain what’s going on and what you can do about it.

Why allergies can develop later in life

Most allergies begin in childhood. But it’s not unusual to start reacting to various triggers later in life. Adult-onset allergies are most common in your 30s and 40s. But they can appear at any age.

Multiple factors could drive the development of allergies, including:

• Repeated exposure to allergens: Ever change your mind about something? Well, your immune system can do the same thing. “Every time you get exposed to an allergen, you could, in theory, develop an immune system reaction to it,” says Dr. Timberlake.
• Hormonal shifts: Significant hormonal fluctuations — like those experienced during puberty, pregnancy and menopause — can change how your immune system behaves around allergens.
• A new allergen exposure: Moving to a new climate or region can sometimes bring on allergies. “It’s a new ecosystem, and your immune system might respond to what it doesn’t recognize,” explains Dr. Pien.
• Stress: A bad day at work or other stressful events won’t cause allergies, but they can weaken your immune system. “When stressors are on your body, something that didn’t bother you before may now throw you over the edge,” says Dr. Timberlake.

In addition, some people are more prone to adult-onset allergies: “If you’ve had eczema or asthma — which both can be allergic conditions — you may be more likely to develop allergies later in life,” notes Dr. Timberlake.

Common adult-onset allergies

So, what sort of allergies might become an issue for adults? Basically, the same types of allergies we talk about at any time of life, including:

• Food allergies: Research shows that about 10% of U.S. adults have a food allergy, and half of those developed during adulthood. Dr. Pien notes that the most common triggers include peanuts, tree nuts and seafood (shellfish and fish).
• Seasonal allergies: Achoo! Trees, pollen, grass and ragweed qualify as some of the most common outdoor allergens. “All of that crud floating in the air can eventually set off your allergies,” says Dr. Timberlake.
• Indoor allergens: Dust mites and mold can bring the same itchy eyes and sneezing that come from outdoor allergens.
• Pet allergies: Even lifelong pet lovers can suddenly react to cats or dogs. Reasons may include owning (and loving) different breeds, increased exposure and gradual immune system changes.
• Insect stings: Most people don’t react strongly the first time they’re stung by a yellow jacket or other stinging insect. But later stings can trigger more serious symptoms. “Sometimes, all it takes is more exposure,” says Dr. Pien.
• Medications: Over time, your immune system may start to view certain medications as a threat and trigger an allergic reaction. It’s common with antibiotics (such as penicillin), pain medications and anticonvulsants.

Symptoms of adult-onset allergies

Many allergic reactions occur right away, while others may be a bit more unpredictable or slowly build. Symptoms often depend on what you’re reacting to, but common signs include:

• Runny or stuffy nose
• Sneezing
• Itchy or watery eyes
• Hives or rash
• Swelling of the lips, face or throat
• Stomach pain, nausea or vomiting
• Difficulty breathing

How adult-onset allergies get diagnosed

The only way to truly confirm an allergy is through testing. Talk to a healthcare provider about testing if you:

• Still have symptoms after trying over-the-counter allergy medications (like antihistamines)
• See a clear pattern with symptoms
• React every time you eat a certain food
• Experience swelling, hives or trouble breathing

“New allergies may take three to five years to develop,” says Dr. Pien. “So, if you haven’t had an allergy test recently, your provider may want to perform one to help you identify any changes.”

Testing also helps sort out look-alikes — non-allergic conditions that mimic allergy symptoms, like chronic nose sensitivity or reactions to temperature changes. (And knowing you DON’T have allergies can help you get the right treatment for whatever is behind your symptoms.)

Managing allergies that develop later in life

Once you know what’s behind your allergy symptoms, you can build a plan to keep them from popping up. Dr. Pien and Dr. Timberlake say there are three main tools:

• Avoidance: The best way to avoid allergic reactions is to avoid the allergens that cause them. Simple adjustments — like using hypoallergenic bedding if dust mites give you trouble — may be enough to limit symptoms.
• Medications: Over-the-counter nasal sprays, antihistamines and decongestants can often tame allergy symptoms. Ditto for eye drops to relieve itchiness. Stronger prescription medications also may be an option.
• Allergy shots: Immunotherapy injections work to retrain your immune system not to respond to certain allergens. These treatments can provide long-term relief from allergens.

Can allergies go away?

There’s always a chance your body will outgrow allergies, but those that show up later in life tend to stick around. (Childhood allergies, on the other hand, often fade away.)

“But even if your allergies hang around, there are ways to treat them and deal with them,” reassures Dr. Timberlake. “Start that conversation with your doctor or allergist. We can help you out.”