All you need to know about the house dust mite
Dust Mite Studies

How to discourage mite infestation indoors

Mites are most active and breed successfully at a temperature of 72 F or 20 C. In this warm indoor environment, a breeding mite must maintain its water weight at 75% in order to function. By reducing the moisture in the indoor air, the active mite will not be able to sustain this weight. Consequently, it will not be able to breed or thrive and the mite colony becomes threatened with extinction.
Indoor humidity, kept below 50% relative humidity, is considered comfortable for humans but hostile to mites. This level of humidity can be achieved by installing effective dehumidifiers or air conditioning. These measures, combined with good ventilation, help to control mite populations. However, there are pockets of mini-environments that may escape this manipulation. These mini-environments include, blankets in a pet's basket, beds and bedding and soft toys or furnishings in regular use. Alternative methods of mite control must be applied. Methods that are cost-effective techniques include; 1. removing carpets in bedrooms 2. covering all beds and bedding with micro-porous mite resistant material 3. using high-filtration vacuum cleaners to control dust 4. using mite killing sprays (Acarosan) on soft furnishings 5. installing high efficiency dehumidifiers in bedrooms. Used in combination these techniques have been proven effective in mite control.
References

Low-allergen environment can be achieved and maintained during pregnancy and in early life', Custovic A et al, 2000, 'J. Clin. Immunol'. 105, No.2, Part 1, pages 252 to 258.

'Reducing relative humidity is a practical way to control dust mites and their allergens in homes in temperate climates'. Arlian LG et al, 2001,J. 'Allergy Clinical Immunol'., Volume 107, Number 1, pages 99-104

'The biology of dust mites and the remediation of mite allergens in allergic disease', Professor Larry G. Arlian and Professor Thomas A.E. Platts-Mills, 2001 'Journal of Allergy and Clinical Immunology', Volume 107, Number 3, Pages S406 to S413