The house dust mite Dermatophagoides pteronyssinus is about half the size of a full-stop or period on a newspaper. It has no sight, no respiratory system and is unable to drink, but lives by absorbing moisture and oxygen from the atmosphere. Mite droppings, which contain digestive enzymes, are a major cause of allergy worldwide. The house dust mite is an ancient creature that has developed a clever method of recycling its food. It uses its droppings as ‘food parcels’. Powerful enzymes in the tiny droppings break down hard-to-digest food for later nourishment. These enzymes cause and trigger allergies in humans by breaking down delicate living tissue.
The mite can produce up to twenty droppings a day, which means approximately 2000 during its active lifetime of up to 3 to 4 months. From eggs to breeding adults, mites pass through six stages of life. The adult female can lay from 60-100 eggs depending upon living conditions, which ideally for breeding mites are warm dark and damp. Most modern conventional beds provide perfect breeding conditions. An important fact to note; the house dust mite’s biological make-up is 75% water. It must maintain this moisture content to breed. Reducing moisture is a threat to its existence.
The house dust mite will not bite. It is a scavenger with a preference for discarded skin scales, but will eat pollen grains, insect scales, bacteria and plant fibres. The mite is a necessary scavenger in nature which man must learn to understand and respect. This simple creature has been on earth for about 23 million years. It came to live with humans only 10,000 years ago.
Mite allergens cross-react within the species. An allergy to one type of mite can cause a reaction to its distant relative. Example: Allergens from house dust mites and storage mites found in grains will cross-react, acting as a single allergy.
For further reading see student research,´The biology of the house dust mite´and Time Line (11) |
