The place where the dust mites find the best conditions to live and to proliferate, is the mattress. Indeed, they find there, dead skin cells (shedding) for food, humidity and warmth. Moreover, the mattress acts like a bellows every time you go to sleep and ejects millions of allergenic microparticles (dust mite droppings) into the air.

Consequently, the cover for mattress is the first cover to buy.

For the pillow and the duvet, covers are necessary only if you cannot wash them regularly (once per month), if possible at more than 55°C.

The pillow cover is the second to get because the it keeps more the warmth and the humidity than the duvet and, because it is less expensive.