Tiny bits of lint, fabric, dead skin cells, pet dander, pollen and other plant matter, drywall, paint particles, carpet fibers, soil, hair, and dust mites. While any of these substances can irritate your nose or throat, some people are truly allergic to dust mite droppings. Dust mites—microscopic bugs that consume dead skin cells of humans and animals—live inside pillows, mattresses, curtains, carpet, and furniture.