For example, a quilted mattress pad over the mattress cover or pillow case that is rarely washed can become infested with mites. Similarly, even though a plastic water bed mattress is obviously immune to mite infestation, the cloth pads used in association with the water bed can become quite infested, as I observed in one home. I f mite allergens are in clothing or bedding, washing and drying will help remove the dust containing the allergens and therefore reduce exposures. Though solvents may not destroy mite allergens, dry cleaning also is an effective way to reduce concentrations because dust levels are reduced by the rinsing and tumbling associated with the process. Mite populations fluctuate with seasons.
Populations are highest in the summer and lowest in the winter.
Mite allergen levels may fluctuate with mite populations but not necessarily, if the allergen level is high in the dust to begin with. Since mite allergens are so stable, they can last in a carpet or bed and cause symptoms for years. Air conditioning has been shown to be an effective way to reduce mite populations in a space. The most likely mechanism is through reduction of relative humidity . Dehumidification of basements in summer and heating in winter, since both reduce relative humidity, are useful ways to limit dust mite populations.