Dust mite - one of the most common allergens in our homes

Common Allergen - Dust Mites

March 28, 2023

The house dust mite, sometimes known as HDM to allergists, is a common allergen and a frequent occupant of human living spaces in almost every Australian home. Dust mites can cause a range of respiratory problems and allergic reactions for those who are sensitive to them.

What is a dust mite?

Dust mites are tiny arachnids that are commonly found in homes, especially in areas where dust and humidity are present. Dust mites feed on dead skin cells shed by humans and pets.

What do dust mites look like?

Dust mites are too small to be seen with the naked eye, as they are only about 0.3 millimeters in size. They have a translucent or whitish body with eight legs and a head that is not clearly defined from the body.

Under a microscope, dust mites can be seen to have a round body with a striated surface, and long hairs that project from their bodies. They do not have eyes, but instead have sensory bristles on their bodies that help them navigate their environment.

While dust mites themselves are not visible, their fecal pellets can be seen as small, dark, and spherical particles. These pellets can accumulate in areas where dust mites are present, such as bedding and upholstered furniture.

Do dust mites bite?

Dust mites do not bite humans or animals. Dust mites are too small to bite, and they do not have the necessary mouthparts to bite or sting. Instead, dust mites feed on the dead skin cells and other organic matter found in household dust. However, dust mites are a common source of allergens that can cause symptoms such as sneezing, runny nose, and itchy eyes in sensitive individuals.

Where do dust mites come from

Dust mites do not originate from outside the home. Instead, they are a natural part of the indoor environment and are commonly found in dust.

According to the American Lung Association, "Dust mites are microscopic, insect-like pests that live in house dust." They are too small to be seen with the naked eye, and can only be seen under a microscope.

Dust mite life cycle

Understanding the life cycle of dust mites is key in controlling their numbers in the home.

The life cycle of a dust mite has four stages: egg, larva, protonymph, and adult. The entire life cycle takes approximately one to three months, depending on environmental conditions such as temperature and humidity.

Adult dust mites have a lifespan of up to four months and can produce 20 to 30 fecal pellets per day. These pellets, along with the dust mites' dead bodies, are a significant source of allergens in the home, causing symptoms such as sneezing, runny nose, and itchy eyes in sensitive individuals.

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