The house dust mite (in some cases described by allergists as HDM) can be described as cosmopolitan guest in human habitation. Dust mites feast upon organic detritus in particular flakes of shed human skin and flourish in the stable natural environment of houses.

House dust mites definitely are a common cause of asthma and allergic symptoms worldwide. The mite’s gut contains a potent digestive enzyme (notably proteases) that persists in their faeces and is a major inducer of allergies which include wheezing. The mites exoskeletons may also bring about allergic attacks.

The European house dust mite (Dermatophagoides pteronyssinus) and the American house dust mite (Dermatophagoides farinae) are two differing species, but aren’t necessarily confined to Europe or The Usa; a 3rd species Euroglyphus maynei also occurs extensively.

The house dust mite survives in every climates, even at high altitude. House dust mites thrive in the indoor environment made available by homes, specially in bedrooms and kitchens. Dust mites survive well in mattresses, carpets, furniture and bedding, with figures around 188 animals/g dust.

Even in dry climates, house dustmites survive and reproduce easily in bedding (specially in pillows), deriving moisture out of the humidity generated by human breathing, perspiration and saliva.

House dust mites devour small particles of organic matter. Like every acari, house dust mites make use of a simple gut; they’ve got no stomach but rather diverticulae, which are sacs or pouches that divert from hollow organs. Like many decomposer animals, they select food that’s been pre-decomposed by fungi.

Allergens generated by house dust mites are among the most common triggers of asthma. Studies have shown the mean attributable fraction of adult asthma due to atopic sensitization was 30% and 18% for sensitization to dust mites. Taken into account this could mean as many as 1.2 billion people may have a certain amount of chronic sensitization to dust mites.

It is commonly believed that the built up detritus from dust mites can add substantially to the weight of mattresses and pillows. While it is true that the faecal matter of dust mites will increase with time, there is no scientific evidence for these claims.
Allergy and asthma victims are also often advised to avoid feather pillows due to the presumed increased presence of the house dust mite allergen . The opposite, however, is true.

A 1996 study from the British Medical Journal has demonstrated that polyester fibre pillows held more than 8 times the total weight of Der p I and 3.57 times more micrograms of Der p I per gram of fine dust than feather pillows.