Allergies in Older Adults: Why They Differ and Medication Cautions

What you need to know

• Allergies can develop for the first time, continue, or change in severity at any age, including later in life.
• Nasal symptoms in older adults can come from allergies, but also from age-related or medication-related rhinitis, so the cause isn't always obvious.
• The American Geriatrics Society's Beers Criteria, a widely used list of medications that carry extra risk for older adults, specifically flags first-generation antihistamines like diphenhydramine due to confusion, falls, and other anticholinergic effects.
• A large study following over 714,000 people with allergic rhinitis found a dose-dependent association between first-generation antihistamine use and dementia risk.
• Second-generation antihistamines (cetirizine, loratadine, fexofenadine) are generally considered the safer oral option for adults 65 and older, since less of the drug reaches the brain.
• New or changing allergy-like symptoms in an older adult are worth a clinician visit, both to confirm the cause and to review medication interactions with other conditions.

Why Allergies Can Be Different Later in Life

It's a common misconception that allergies are something you only develop as a child and outgrow with age. In reality, allergic rhinitis can develop for the first time in adulthood, including later in life, and existing allergies can change in pattern or severity over time. At the same time, other common causes of nasal congestion become more frequent with age — including non-allergic rhinitis and rhinitis related to certain blood pressure or other medications — which can make it harder to tell what's actually driving symptoms without a closer look.

Why Medication Choice Matters More With Age

The American Geriatrics Society's Beers Criteria is a widely used, expert-reviewed list of medications considered potentially inappropriate for older adults because the risks tend to outweigh the benefits in this age group. First-generation antihistamines, including diphenhydramine, are specifically listed: they are strongly anticholinergic, are cleared from the body more slowly with age, and are associated with confusion, dry mouth, constipation, and a higher risk of falls in older adults. A large study of more than 714,000 people with allergic rhinitis also found that first-generation antihistamine use was associated with a dose-dependent increase in dementia risk.

Second-generation antihistamines — cetirizine, loratadine, and fexofenadine among them — are generally considered the safer oral category for adults 65 and older, largely because much less of the medication crosses into the brain, reducing sedation and cognitive effects. This is general information, not a personal recommendation; other health conditions and medications can still affect which option is appropriate for you.

Other Considerations With Age

Older adults are more likely to be managing other conditions and medications at the same time as allergy symptoms, which raises the chance of an interaction or an effect that wouldn't be as noticeable in a younger adult (for example, certain antihistamines and decongestants can affect blood pressure, glaucoma, or urinary symptoms related to an enlarged prostate). This is a good reason to review any new allergy medication, including OTC options, with a pharmacist or clinician who knows your full medication list.

When to seek care

Practical next steps

Safe general steps

1. Track when and how your symptoms happen to help distinguish allergies from other causes
2. Review your current allergy medications with a pharmacist or clinician, especially if you take diphenhydramine or other first-generation antihistamines
3. Ask about second-generation antihistamine options if you're currently using an older-generation product
4. Mention any new confusion, dizziness, or fall after starting or changing an allergy medication

Actions that need medical guidance

• Switching from a first-generation to a second-generation antihistamine
• Sorting out whether symptoms are allergies, non-allergic rhinitis, or medication-related
• Managing allergy symptoms alongside other conditions like glaucoma, high blood pressure, or an enlarged prostate

Frequently asked questions

Sources

1. American Geriatrics Society — 2023 AGS Beers Criteria for Potentially Inappropriate Medication Use in Older Adults
2. GoodRx Health — Medications on the Beers List: What Older Adults Should Avoid
3. ACAAI Patient — Allergic Asthma

Medical disclaimer: This guide is for general education and isn't a substitute for personalized medical advice. It doesn't provide dosing. Always talk to a qualified healthcare professional about your symptoms and treatment.

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