New allergies can develop at any stage of life

Allergy Awareness Week 2025 is here and Allergy UK is launching the campaign ‘I Wish I Knew…’ to highlight the experiences of people living with allergies and raise awareness of allergy and its impact. We're starting with the first fact: Allergies can strike at any age The other 2 topics we'll cover this week:

An allergy can make other health conditions such as Asthma worsen
Getting a diagnosis for an allergy matters: it is the key to accessing the right care

Stay tuned for more updates

Did you know?

Allergies are often thought of as something that begins in childhood, but that is far from the full picture. In reality, many people develop allergies for the first time as adults, and even later in life. Whether it’s an unexpected reaction to pollen or a food you’ve always eaten without trouble, it is entirely possible to become allergic at any age.

Woman with gray hair smiling, wearing a white shirt. Text: "Allergies can strike at any age." Gray background, colorful border. — Allergies can strike at any age from a mix of exposure factors

Why do allergies appear later in life?

There is no single explanation, but a mix of environmental exposure, lifestyle changes and shifts in the immune system are thought to play a role. Adult-onset allergies are becoming increasingly recognised, especially as awareness and diagnosis improve.

Contributing factors may include:

New environments: Moving to a different area or country can expose you to unfamiliar allergens such as different types of pollen or mould.
Immune system changes: The immune system becomes less balanced over time and may start reacting to substances it once ignored.

Cumulative exposure: Some people only develop symptoms after years of contact with an allergen.

Stress and illness: Major life changes or recovery from illness can shift the immune system into a more reactive state.

A 2019 study published in JAMA Network Open found that nearly half of adults with food allergies reported developing at least one of them during adulthood.

What kinds of new allergies can start in adulthood?

People can develop allergies to a range of substances that they may have previously tolerated without any issue.

Some of the most common include:

Man holding a small, fluffy dog with tan and white fur. The dog looks content, tongue out, set against a blurred green background. — Indoor allergens such as pet dander can trigger allergies later in life

Pollen: Tree, grass and weed pollen can all trigger hay fever symptoms later in life.

Food: Shellfish, nuts, fruit, dairy and even wheat are frequent triggers in adults.
Insect stings: Reactions to bees or wasps can become more serious with age.

Indoor allergens: Pet dander, dust mites and mould are common sources of sneezing, itchy eyes or skin irritation.

What about allergies in older adults?

Yes, older adults can develop allergies too. In fact, they may go unnoticed for longer because symptoms can overlap with other age-related issues.

Symptoms can be mistaken for medication side effects or infections

Skin becomes more sensitive and reactive with age

Existing conditions can mask allergy-related symptoms

A review published in the Journal of Allergy notes that the aging immune system may both increase the risk of allergic reactions and make them harder to recognise (Pfaar et al., 2017).

What should you do if you suspect an allergy?

Track your symptoms: Keep a simple record of when symptoms occur, what you ate, and what was in your environment.

Woman and child in black shirts smile in a sunlit park with green grass and autumn trees, creating a warm, cheerful mood. — Keep a record of allergies for your family as they show symptoms

Speak to a healthcare professional: They may refer you for testing to confirm or rule out an allergy.

Avoid self-diagnosing: It is important to get clear guidance, especially when symptoms are mild or unusual.

Don’t ignore new symptoms: Something as simple as regular sneezing or itchy skin could signal a developing allergy.

Why early recognition matters

If you have developed a new allergy, identifying it early means you can manage it more effectively. This might involve lifestyle adjustments, medical treatment or simply avoiding the trigger. Most importantly, it can help prevent symptoms from worsening over time.

As Allergy Awareness Week 2025 reminds us, allergies do not have a set timeline. Whether you are in your 30s, 50s or older, new allergies can develop and should not be ignored. Recognising the signs is the first step toward getting the right care.

Curious about what allergens are causing your symptoms?

Illustration of a lab report on allergens, featuring a green microscope, charts, and icons of a bug, plants, and a dog. Background in gradients. — 295+ Allergy Test Kit from AllergyRhino

Find out by taking this comprehensive allergy blood test screens for +295 allergens, including tree pollen, grass and weed pollen, mites, cat and dog, fur, insect venoms, moulds, yeasts, food and latex, helping you pinpoint triggers and find long-term relief.

If your allergies get worse every year, or you're tired of relying on daily tablets, you might be a candidate for SLIT (sublingual immunotherapy). It’s a once-daily tablet that helps retrain your immune system to become less reactive to pollen over time. Many people find their symptoms significantly reduced within the first year, with long-term benefits that can last even after treatment ends.