Why do I have allergy symptoms all year round?

Sneezing, a blocked nose and itchy eyes are often associated with hay fever during spring and summer. However, some people experience these symptoms throughout the year, even when pollen levels are low.

Year round allergies can occur when you're regularly exposed to allergens found indoors, such as house dust mites, pet dander and mould spores.

This is known as perennial allergy, and when it affects the nose, it is often called perennial allergic rhinitis.

Understanding why symptoms continue outside the usual pollen season can help you recognise possible triggers, manage exposure and decide when allergy testing or medical advice may be appropriate.

Key takeaways

• Year round allergies can cause sneezing, nasal congestion, a runny nose and itchy eyes throughout the year.

• Common indoor allergens include house dust mites, pet dander and mould spores.

• Seasonal and perennial allergies can occur together, making symptoms worse at certain times of year.

• Persistent nasal symptoms are not always caused by allergies, as non-allergic rhinitis can produce similar problems.

• Allergy testing may help identify sensitisation to particular allergens, but results must be interpreted alongside symptoms and medical history.

What are year round allergies?

Year round allergies, also called perennial allergies, occur when the immune system reacts to allergens that may be present throughout the year.

Unlike seasonal hay fever, which is commonly associated with pollen exposure during particular months, perennial allergies can cause symptoms regardless of the season.

When an allergen triggers an allergic response, the immune system releases substances including histamine. These contribute to symptoms such as sneezing, itching and nasal inflammation.

The symptoms may be constant or come and go depending on exposure.

For example, someone with a house dust mite allergy might notice symptoms when waking up, while someone allergic to animal dander may experience problems after spending time around pets.

What causes allergy symptoms all year round?

Several environmental allergens can remain present indoors throughout the year.

House dust mites

House dust mites are microscopic organisms commonly found in bedding, mattresses, upholstered furniture and carpets.

They feed on shed human skin cells and tend to thrive in warm, humid environments.

Allergic reactions are triggered by proteins associated with the mites, including those found in their waste particles.

People with dust mite allergies may notice:

• Sneezing when waking up

• A blocked or runny nose

• Itchy eyes

• Symptoms when changing bedding or disturbing dust

• Coughing or wheezing in some cases

Dust mite exposure can occur throughout the year, although indoor humidity and other environmental conditions can influence mite populations.

Pet dander

Cats, dogs and other animals can produce allergens found in skin flakes, saliva and other bodily secretions.

These allergens may become airborne or collect on furniture, carpets and clothing.

Pet allergies can cause persistent symptoms when someone lives with an animal or regularly visits environments where animal allergens are present.

Importantly, the problem is not simply pet fur. Allergenic proteins can remain in the environment even when an animal is not in the room.

Symptoms may include sneezing, itchy eyes, nasal congestion and, in susceptible individuals, wheezing.

Mould spores

Mould can grow in damp environments, particularly where there is condensation, poor ventilation or water damage.

Common locations include bathrooms, kitchens, poorly ventilated rooms and areas affected by leaks.

Some people are allergic to airborne mould spores, which can trigger nasal and respiratory symptoms.

However, not every person experiencing symptoms in a damp property has a mould allergy.

Mould exposure can also irritate the respiratory system without involving an allergic response.

Mould levels vary with environmental conditions, so symptoms may fluctuate throughout the year.

Other indoor allergens

Other possible triggers include allergens associated with insects, such as cockroaches, although exposure varies considerably between homes and locations.

Indoor environments may also contain pollen brought inside through open windows, clothing or pets.

The presence of an allergen does not automatically mean it is causing symptoms. Clinical assessment is needed to establish whether an allergy is relevant.

What are the symptoms of perennial allergies?

Perennial allergic rhinitis commonly affects the nose and sometimes the eyes.

Symptoms can include:

• Frequent sneezing

• A persistently blocked nose

• A runny nose

• Itching inside the nose

• Itchy, red or watery eyes

• Mucus dripping down the back of the throat

• Coughing associated with nasal symptoms

• Disturbed sleep caused by congestion

Symptoms can range from mild irritation to problems that interfere with concentration, sleep and everyday activities.

Some people also have asthma or eczema alongside allergic rhinitis, although these are separate conditions and should be assessed appropriately.

If you regularly experience wheezing, chest tightness or breathlessness, seek medical advice rather than assuming these symptoms are simply part of hay fever.

What is the difference between seasonal and perennial allergies?

The main difference is when exposure to the relevant allergens occurs.

It is also possible to have both types of allergy.

For example, someone allergic to dust mites and grass pollen may experience nasal congestion throughout the year, with additional sneezing and eye irritation during summer.

This overlap can make it difficult to identify the cause from symptom timing alone.

Why are my allergies worse indoors?

If symptoms become more noticeable indoors, allergens within the home may be contributing.

House dust mites can accumulate in bedding and soft furnishings, while animal allergens may settle on furniture and remain airborne.

Damp areas may also contain mould.

However, indoor symptoms are not always allergic.

Cleaning products, fragrances, tobacco smoke and changes in temperature or humidity can irritate the nose and airways.

It may help to notice whether symptoms worsen in particular rooms, during cleaning or after contact with animals.

These observations can provide useful information to discuss with a healthcare professional.

Can you develop year round allergies as an adult?

Yes. Allergies can develop at different stages of life, including adulthood.

Someone who previously had no noticeable symptoms around pets or dust mites may develop allergic rhinitis later.

Changes in exposure, living environment and individual immune responses may contribute.

However, developing a blocked or runny nose as an adult does not necessarily mean a new allergy is responsible.

Other explanations, including non-allergic rhinitis, medication effects or nasal conditions, may need to be considered.

If symptoms are new, persistent or worsening, a clinician can help investigate the cause.

Are persistent allergy symptoms always caused by an allergy?

No. Several conditions can produce symptoms similar to perennial allergic rhinitis.

One example is non-allergic rhinitis, where the nose becomes irritated or inflamed without an allergic immune response.

Possible triggers include:

• Strong fragrances

• Smoke

• Changes in temperature

• Changes in humidity

• Certain medications

• Irritating airborne substances

Other causes of persistent nasal congestion may include chronic sinus inflammation, nasal polyps or structural problems affecting the nose.

This is why it is important not to assume that every blocked nose or episode of sneezing is caused by an allergy.

A healthcare professional can assess your symptoms and recommend appropriate investigations where needed.

How are year round allergies diagnosed?

Diagnosing an environmental allergy usually begins with a review of your symptoms and medical history.

A healthcare professional may ask:

• When symptoms started

• Whether they occur throughout the year

• Where symptoms are most noticeable

• Whether you have pets

• Whether symptoms worsen in bed or during cleaning

• Whether you have asthma, eczema or other allergic conditions

• Whether symptoms improve away from particular environments

Where appropriate, allergy investigations may include skin prick testing or blood tests measuring allergen-specific immunoglobulin E (IgE) antibodies.

These tests assess sensitisation to particular allergens.

However, a positive allergy test does not automatically confirm that an allergen is responsible for your symptoms.

Results must be considered alongside your clinical history and pattern of exposure.

Can an environmental allergy test help identify possible triggers?

Environmental allergy testing may be useful when symptoms suggest an allergic cause but the relevant allergens remain unclear.

Ready Health offers an environmental allergy at-home test kit that measures specific IgE antibodies against 19 environmental allergens.

The environmental panel includes:

• Tree, grass and weed pollens

• Cat, dog and horse dander

• Two house dust mite allergens

• Cockroach allergen

• Cladosporium mould allergen

The test uses a finger-prick blood sample collected at home and returned for laboratory analysis. The same kit also includes testing for 23 food allergens.

Importantly, the mould component measures sensitisation to Cladosporium specifically, rather than testing for every type of mould that may be present in a home.

A positive result indicates sensitisation, but does not independently establish a clinical allergy or explain every symptom.

The panel also does not cover every possible environmental allergen.

Ready Health states that the test is suitable for people aged four and over, but not during pregnancy or breastfeeding. People with a diagnosed severe allergy or a prescribed adrenaline auto-injector are advised to consult their GP before ordering.

Results should be discussed with an appropriately qualified healthcare professional, particularly when symptoms are persistent or affecting everyday life.

How can you reduce exposure to indoor allergens?

If an environmental allergy is suspected or confirmed, reducing relevant exposure may help manage symptoms.

The most appropriate measures depend on the allergen involved.

Reducing house dust mite exposure

Practical measures may include:

• Washing bedding regularly according to care instructions

• Using allergen-impermeable mattress and pillow covers

• Reducing unnecessary dust-collecting clutter

• Cleaning surfaces with a damp cloth

• Maintaining appropriate indoor ventilation and humidity

These steps may reduce exposure, but no single household measure is guaranteed to eliminate symptoms.

Managing pet allergen exposure

For people sensitive to animal allergens, possible measures include keeping pets out of bedrooms, cleaning regularly and reducing contact where practical.

Animal allergens can remain on surfaces and clothing, so occasional cleaning may not completely remove exposure.

If symptoms are significant, seek personalised advice about managing exposure.

Addressing damp and mould

Where mould is present, the underlying moisture problem should be addressed.

This may involve improving ventilation, managing condensation or repairing leaks.

Simply cleaning visible mould without resolving the source of damp may not prevent it from returning.

Anyone experiencing persistent respiratory symptoms in a damp environment should seek appropriate medical advice.

What treatments are available for perennial allergic rhinitis?

Treatment depends on the symptoms, their severity and whether an allergy has been established.

Options that healthcare professionals may recommend include:

• Non-sedating antihistamines

• Corticosteroid nasal sprays

• Saline nasal rinses

• Measures to reduce exposure to relevant allergens

Nasal corticosteroid sprays are commonly used for persistent allergic rhinitis, particularly when congestion is a major symptom.

The choice of treatment depends on individual circumstances, including age, other medical conditions and current medication.

Some people with significant symptoms may benefit from specialist assessment to consider additional options, including allergen immunotherapy where appropriate.

Avoid relying on decongestant nasal sprays for prolonged periods, as some can cause rebound congestion when used beyond their recommended duration.

A pharmacist or clinician can advise on suitable treatments and correct use.

When should you see a doctor about year round allergy symptoms?

Consider arranging a medical assessment if:

• Symptoms persist despite reasonable self-care

• Nasal congestion affects your sleep

• You frequently experience sinus symptoms

• You are unsure whether allergies are responsible

• Symptoms interfere with work, school or daily activities

• You have asthma alongside suspected allergies

• Symptoms are worsening or changing

A clinician can assess whether allergic rhinitis, non-allergic rhinitis or another condition may be involved.

Call 999 immediately if you suspect anaphylaxis or experience severe breathing difficulties. Signs of anaphylaxis may include sudden breathing problems, throat or tongue swelling, feeling faint or collapsing. Not everyone experiences all these symptoms, and visible swelling does not need to be present.

Do not delay emergency treatment while trying to identify a possible allergen.

Understanding and managing allergies throughout the year

Allergy symptoms that continue outside the usual hay fever season may be associated with indoor allergens such as dust mites, pet dander or mould spores.

However, persistent symptoms are not always caused by an allergy, and identifying the underlying problem may require clinical assessment.

Paying attention to where and when symptoms occur can help you recognise possible patterns.

If symptoms continue, discussing them with a healthcare professional can help determine whether allergy testing or other investigations are appropriate.

Ready Health provides a range of health tests and checks, including environmental allergy testing, alongside access to private clinician appointments.

Understanding the possible cause of your symptoms is an important step towards choosing an appropriate approach to managing them.

FAQs

Why do I have hay fever symptoms in winter?

Hay fever-like symptoms during winter may be associated with indoor allergens such as dust mites or pet dander. Non-allergic rhinitis, respiratory infections and other conditions can also cause similar symptoms.

Can dust mites cause allergies all year round?

Yes. House dust mites can be present indoors throughout the year, particularly in bedding, mattresses and soft furnishings. People who are allergic to them may experience persistent nasal or eye symptoms.

Can pet allergies develop suddenly?

Pet allergies can become noticeable in adulthood, even after previous exposure without obvious symptoms. However, new symptoms around animals should not automatically be assumed to indicate an allergy.

Can mould cause year round allergy symptoms?

Some people develop allergic reactions to mould spores, which can be present in indoor environments. Mould and damp conditions may also cause respiratory irritation without an allergic response.

How do I know if I have perennial allergic rhinitis?

Symptoms such as persistent sneezing, a blocked or runny nose and nasal itching may suggest perennial allergic rhinitis. A healthcare professional can review your symptoms and determine whether allergy testing is appropriate.

Will an allergy blood test confirm what I am allergic to?

An allergen-specific IgE blood test can identify sensitisation to particular allergens. However, a positive result does not necessarily mean that exposure causes symptoms. Diagnosis requires interpretation alongside your medical history.