The Facts

We live surrounded by filth. Sorry, but it's a fact. All human beings shed about 5-10 grams of dead skin each week. About 80% of the material you see floating in a sunbeam is actually flakes of skin. Whether it's a home or an hotel dust mites are nearly universal in occurrence - a typical bed mattress may contain anything from 100,000 to 10 million mites.

Dust Mites in Beds (Dermatophagoides pteronyssinus)

Ten to 20 percent of the weight of a two year old pillow can be composed of dead mites and their droppings. Carpets and upholstery also support high mite populations. What do house dust mites eat? Human and animal skin flakes (Dermatophagoides - "skin eater"). So in some ways house dust mites are a good thing - they help stop us drowning in our own (naturally occurring) filth.

So why are we interested in dust mites?

House dust is a strongly allergenic material because it is usually heavily contaminated with the faecal pellets and skins of Oermatophagoides. Some estimates are that dust mite allergens factor in 50-80% of asthmatics, as well as in eczema, hay fever and other allergic conditions. Exposure of the skin or respiratory tract to proteins is frequently associated with allergic sensitization. The wheeze-inducing proteins are digestive juices from the mite gut which are quite potent.

The proteolytic activity of Der p I, the group I allergen of Dermatophagoides pteronyssinus, may influence the allergenic of mites.

Exposure to the mites in the first, crucial year of life can trigger a lifelong allergy. There is no cure, only prevention - controlling house dust mite populations - focusing on dust control, to reduce the concentration of dust-borne allergens in the living environment by controlling both allergen production and the dust which transports it.

Allergic Rhinitis (Most common form Hay fever)

Allergic rhinitis can directly interfere with daily activities and be associated with significant impairments of quality of life.

Patients with allergic rhinitis frequently present with symptoms of nasal congestion, runny nose, sneezing, daytime somnolence and fatigue associated with decreased cognitive performance and impaired quality of life.

Recent research has suggested that daytime somnolence in allergic rhinitis can be attributed to chronic inflammation of the nasal mucosa leading to nasal congestion and obstructed nasal passageways resulting in deterioration of nocturnal sleep and daytime sleepiness. If untreated, allergic rhinitis can result in considerable health-related and economic consequences.

Allergic rhinitis can also be related to significantly impaired psychological well-being and to perceived impaired cognitive functioning. Allergic patients may temporarily put more effort into sustaining performance, resulting in earlier exhaustion, which impairs psychological well-being.

These facts are other arguments for preventing or treating of any allergic rhinitis.

Over (tie last 30 years, the prevalence of allergies has been increasing. Currently, in the industrialised countries, this prevalence ranges from 25% to 40% for allergic rhinitis and 20% for allergic asthma (some studies would nevertheless tend to indicate that allergic asthma prevalence may be stabilising). All of these figures demonstrate the challenge that allergic disorders represents for public health, and the need to better understand them in order to improving their management.

• Allergic reactions to house dust mite cause sneezing, wheezing, runny nose, tight chest and skin rashes, avoidance measures are key as part of a management programme.

• The house dust mites thrives in a warm moist environment; house dust mites will not thrive in a nice dry bed.

• Padded headboards attract and hold dust, they either need to be vacuumed regularly or a wooden one installed instead.

• Indoor air quality is often as much as 20 times more polluted than the air outside. Common allergens are house dust mite, mould spores and pollen. Certain cleaning products can also trigger a reaction.

• House dust mites can survive at quite low temperatures and up to more than 34C, but they need moisture to survive, which is why our UK humid climate is so good for them.