A Closer Look at Dust Mites

Since dust mites play such a large role in allergies, we thought we'd take a closer look. Here are some possibly little known facts provided by the Medical Entomology Center about these tiny creatures that give us such trouble:

• Adult female dust mites are a mere 0.3 mm long; males are slightly smaller and thinner.
• Dust mites are mainly translucent.
• As arachnids, dust mites are in the same family as spiders and scorpions. They have eight legs.
• Because they lack an exoskeleton, dust mites are vulnerable to water loss. This is why they favor humid conditions, like beds.
• Dust mites have no eyes.
• Favorite habitats include mattresses or pillows because of the constant source of skin scales. Humans shed about one gram of skin a day while sleeping. We also produce about a pint of water in sweat every night, providing the high humidity that dust mites love. Dust mites also live in carpets, furniture, cushions, clothes, and stuffed animals.
• Adult females lay between 40-80 eggs in their lifetime. Eggs hatch into larval nymphs, which molt into two nymphal stages before reaching adulthood. Adults live between one and three months. Temperature and humidity affect both the speed of development and adult longevity.
• Dust mites produce around 2,000 fecal pellets in their lifetime, each of which contains digestive enzymes; it is these enzymes that people are allergic to.

To reduce dust mite allergen in the home, the Medical Entomology Centre recommends the following:

• Wash pillows and bedclothes regularly, at high temperatures if possible. If high temperatures are not an option, you can freeze pillows before washing them.
• Leave bedclothes turned back during the day.
• Use barrier fabrics, dehumidifiers, and steam cleaners.
• Vacuum mattresses, carpets, upholstery, etc. thoroughly.
• Replace mattresses and pillows that are over 10 years old.
• Use anti-allergen sprays.
• Put air filters around the home.