[Medical Q&A] What exactly are dust mites that often cause allergies?

Author: Wang Ling Children's Hospital Affiliated to Chongqing Medical University

Reviewer: Niu Chao, deputy chief physician, Children's Hospital Affiliated to Chongqing Medical University

The dust mites that cause allergies are mainly house dust mites, which include dust mites and household dust mites.

Dust mites are tiny arthropods, as small as a pinhead, difficult to detect with the naked eye, and look like spiders under a microscope, with a body length of 0.1 to 0.4 mm. Dust mites do not bite people, and for those who are not allergic to dust mites, these tiny bugs are harmless.

Dust mites like to live in warm (15-35℃), humid (55%-80%), and dark environments. They are extremely sensitive to changes in ambient temperature and humidity. The development and activity of dust mites will stop when the temperature is below 10℃, and they will die when the humidity is below 50%. Dust mites like to eat powdery substances, such as human dandruff, flour, milk powder, pollen, etc. They like to hide in dusty places, such as quilts, mattresses, bedding, pillows, fabric sofas, carpets, curtains, plush toys, and pet hair in the bedroom. Therefore, plush toys are the favorite of children and dust mites. On an ordinary double bed, the number of dust mites can be more than 2 million, and there are 1,000 to 10,000 mites and excrement in 1 gram of bed dust. The number of dust mites on the surface of a newly bought or long-unused mat or on the air conditioner filter that has not been cleaned for 7 days will also exceed tens of thousands. On a carpet that is vacuumed regularly and carefully, there may still be 1,000 to 10,000 mites per square meter. Dust mites are light and can float in the air, so as long as the temperature and humidity are suitable, dust mites can be found everywhere in the home.