Killing dust mites in pillows is relatively easy compared to the harder task of dealing with dust mites in mattresses.
This is because pillows are smaller and portable.
The build up of mites and their droppings can happen very quickly without regular attention so it pays to deal with your pillows frequently.
Dust mites will die in exposure to direct sunlight. Leave your pillows outside on a sunny day to absorb the rays and you will remove the dust mite population.
Again wash them afterwards to remove the bodies.
Often people do not realize that you can wash pillows. You can. Just read the label and follow the directions. Different pillow materials have different needs. Down for example needs to be dry cleaned but most pillows can go through a normal wash. Dust mites will be killed by a hot wash.
To ensure that mold does not form make sure they get put through the dryer to ensure the inside is completely moisture free. The drying cycle will also kill dust mites.
You can purchase allergy covers for your pillows that protect you from dust mites. These casings are so tight that even a dust mite and its droppings cannot pass through the fibers. This protects you from the mites in your pillow by providing a barrier but also kills the mites because it denies them from their food source.
Another way to kill dust mites in pillows is to freeze the pillows for 24 hours. Remove the washable cover and if you want place them in a plastic bag for protection.
After you have frozen your pillows you will have to wash them to get rid of all the dead mites. Otherwise they will just remain in the pillow.
Even if you don't wash the pillows first just run them through a cycle in the dryer on the hottest temperature. Dust mites die from heat whether it is a hot wash, sunlight or a hot drying cycle.