For allergy sufferers, pillows can be a source of problems. Dust, body oil, perspiration and dead skin particles gather on (and inside) pillows. Pillows also harbour dust mites — microscopic organisms to which many people are allergic. If you have goose down, dust and dirt act as abrasives and shorten the life of the down. So at least twice a year, give your pillows a good cleaning. Here’s how.