Do mattress protectors help with allergies?

Yes, particularly against dust mites, a common trigger for allergies and asthma. Dust mites feed on skin cells and thrive deep inside mattresses; a tightly woven or encasement-style protector blocks them from colonising the mattress and makes it easy to wash away allergens on the surface. For the strongest effect, choose a full encasement labelled allergen or dust-mite barrier, and wash it regularly along with your sheets in warm water.