What Are the Common Symptoms of House Dust Mite Allergy?

House dust mite allergy is one of the most common causes of year-round (perennial) allergic symptoms in the UK. Unlike hay fever, which tends to follow the pollen season, house dust mite allergy can cause symptoms throughout the year — often worse at night or first thing in the morning.

Many people are unaware that their persistent sneezing, blocked nose, or itchy eyes are caused by an allergy rather than repeated colds. Understanding the symptoms, and knowing when to seek specialist help, can make a significant difference to quality of life.

At The London Allergy Clinic, we offer specialist allergy assessment and treatment for adults and children at our clinics in Marylebone, Fitzrovia, and High Barnet.

What Is a House Dust Mite?

House dust mites are microscopic creatures that live in household dust. They are found in virtually every home in the UK, thriving in warm, humid environments — particularly in bedding, mattresses, carpets, and upholstered furniture. They feed on shed human skin cells.

Importantly, it is not the mite itself that causes the allergic reaction. It is the proteins found in the mite's droppings (faecal particles) that trigger the immune response. Each mite produces around 20 droppings per day, and these particles remain allergenic even after the mite has died — meaning symptoms can persist regardless of how thoroughly a home is cleaned.

House Dust Mite Allergy Symptoms: Allergic Rhinitis (Nasal Symptoms)

The most common presentation of house dust mite allergy is allergic rhinitis — inflammation of the nasal passages triggered by allergen exposure. Symptoms include:

• Frequent sneezing, particularly in the morning or after waking

• A runny nose (rhinorrhoea) — often producing a clear, watery discharge

• Nasal congestion or a persistently blocked nose

• Itching of the nose, roof of the mouth, or throat

• Postnasal drip — mucus running down the back of the throat, which can cause a persistent cough

• Facial pressure or discomfort, particularly around the sinuses

Because these symptoms are perennial — present all year round — they are easily confused with recurrent colds or sinusitis. If you find your symptoms never fully resolve, or are consistently worse at home or in bed, a dust mite allergy may be the underlying cause.

Eye Symptoms: Allergic Conjunctivitis

Many people with house dust mite allergy also experience allergic conjunctivitis — inflammation of the membrane covering the eye (the conjunctiva). When both nasal and eye symptoms occur together, this is termed allergic rhinoconjunctivitis. Eye symptoms include:

•       Red, itchy, or watery eyes

•       A gritty or burning sensation in the eyes

•       Swollen or puffy eyelids

•       Sensitivity to light

These symptoms can significantly affect concentration and daily functioning, particularly in children. They are frequently mistaken for an eye infection, but unlike an infection, they do not produce a thick or coloured discharge.

Chronic and More Serious Symptoms

Where house dust mite allergy goes unrecognised or untreated, symptoms can become chronic and extend beyond the nose and eyes to affect the lower airways and overall health.

Upper Airway Inflammation and Sinusitis

Persistent inflammation of the nasal passages can cause swelling that blocks the sinuses — the hollow spaces in the skull connected to the nasal cavity. This can lead to recurrent sinusitis, characterised by facial pain or pressure, headaches, and reduced sense of smell. Chronic nasal obstruction can also result in mouth breathing, disrupted sleep, and snoring.

Asthma

House dust mite allergy is closely associated with asthma. According to Allergy UK, when allergic rhinitis is not recognised and treated, it can extend to the lower airways and trigger or worsen asthma. Asthma symptoms caused or worsened by dust mite allergy include:

•       Wheezing or a whistling sound when breathing

•       Shortness of breath

•       Chest tightness

•       A persistent, dry cough — particularly at night

People with both dust mite allergy and asthma often find their asthma is more difficult to manage. Specialist allergy assessment can identify the trigger and enable targeted treatment.

Our Children's Asthma Service with Dr Tammy Rothenberg can help to diagnose the problem and offer management solutions.

Eczema

In children, house dust mite allergy can also be associated with eczema (atopic dermatitis). Exposure to dust mite allergens can trigger or worsen skin flares, leading to itchy, inflamed, or broken skin. The combination of eczema, asthma, and allergic rhinitis is sometimes referred to as the 'atopic triad'.

Our Children's Eczema service with Dr Emily Derrick provides specialist assessment for children affected by this condition.

Fatigue and Impact on Daily Life

Disrupted sleep caused by nasal congestion, coughing, or itchy skin can lead to persistent fatigue, difficulty concentrating, and reduced quality of life. Allergy UK notes that many people suffer in silence, not realising that their symptoms are both allergy-related and treatable.

How Is House Dust Mite Allergy Diagnosed?

A specialist allergy assessment begins with a thorough clinical history. This is typically followed by one or both of the following tests:

•       Skin prick testing — a small amount of dust mite allergen is introduced to the skin; a positive result produces a small raised weal (bump) within 15–20 minutes

•       Specific IgE blood test — measures the level of allergen-specific antibodies in the blood

At The London Allergy Clinic, we offer both diagnostic tests as part of a comprehensive allergy consultation. Accurate diagnosis is the essential first step in determining the right course of treatment.

Management and Treatment Options

Allergen Avoidance

Reducing exposure to house dust mite allergens is a recommended first step, though it is difficult to eliminate them entirely. Practical measures include:

•       Washing bedding at 60°C or above weekly

•       Using allergen-impermeable covers on mattresses, duvets, and pillows

•       Replacing carpets with hard flooring where possible

•       Vacuuming with a HEPA-filter vacuum cleaner

•       Reducing indoor humidity through ventilation

These measures may reduce symptoms in some people, but are unlikely to be sufficient as a standalone treatment for moderate to severe allergy.

Medication

A range of prescription and over-the-counter medicines can help manage symptoms:

•       Intranasal corticosteroid sprays — the most effective treatment for nasal symptoms when used regularly and with correct technique. Examples include fluticasone and mometasone.

•       Non-sedating antihistamines — useful for sneezing, itch, and 'wet' nasal symptoms. May be used alone for mild disease or in combination with a nasal spray for more severe symptoms.

•       Eye drops — used for allergic conjunctivitis, either alone or alongside an antihistamine.

•       Saline nasal rinses — a useful adjunct to relieve congestion and wash out allergens.

Where symptoms are not adequately controlled by initial treatments, a specialist may consider a short course of oral corticosteroids to provide rapid relief, or escalate to a combined intranasal corticosteroid/antihistamine spray.

Allergen Immunotherapy (Desensitisation)

For patients with moderate to severe house dust mite allergy who do not achieve adequate control with medication alone, allergen immunotherapy offers the possibility of long-term improvement by addressing the underlying cause of the allergy — not just the symptoms.

Immunotherapy works by exposing the immune system to gradually increasing doses of the allergen, building tolerance over time. There are two main forms:

•       Subcutaneous immunotherapy (SCIT) — a series of injections given at a clinic, typically over a course of 3 years

•       Sublingual immunotherapy (SLIT) — allergen tablets or drops taken under the tongue daily at home, for 3 years.

Immunotherapy is specialist-initiated and requires confirmed IgE-mediated sensitisation to house dust mite. It is generally suitable for adolescents and adults. It is not appropriate for patients with severe or uncontrolled asthma.

The London Allergy Clinic offers desensitisation treatment for eligible patients. A full consultation and diagnostic assessment is required before immunotherapy can be recommended.

Speak to a specialist at The London Allergy Clinic. We offer consultations for adults and children at our Marylebone, Fitzrovia, and High Barnet clinics.

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