The house dust mite (Dermatophagoides pteronyssinus), sometimes abbreviated by allergists to HDM, is a cosmopolitan guest in human habitation. It is more common in Europe than North America, where it is replaced by D. farinae. The mite thrives in modern fully-carpeted, double-glazed, draught-proof homes, and is comfortable at 25C, 75% relative humidity.
The mite lives on shed human skin cells, predigested by the fungus Aspergillus repens. It is particularly common in carpets and bedding.
The house dust mite is one of the most important allergens, implicated in allergic asthma, rhinitis, conjunctivitis and dermatitis. The protein responsible for the allergic reaction is DerP1, a protease digestive enzyme found in mite feces.
Measures to control house dust mite include:
Regular vacuum cleaning (especially with high-efficiency particulate air (HEPA) filters)
Regular damp dusting of surfaces
Replacement of carpets with vinyl flooring
Covering of mattresses and pillows with impervious materials
Daytime internment of teddy bears in a freezer
Use of chemicals (acaricides) to kill mites
Use of fungicides to kill Aspergillus
These measures, while reducing numbers of HDM and amounts of allergen, seem to have only marginal effects on allergic symptoms.
External links
House Dust Mite Avoidance in Asthma: Cochrane (http://www.update-software.com/abstracts/ab001187.htm)
House Dust Mite Avoidance in Rhinitis: Cochrane (http://www.update-software.com/abstracts/ab001563.htm)
Estimates are that dustmites may be a factor in 50 to 80 % of asthma cases, as well as in countless cases of eczema, hay fever, and other allergic ailments.
Dustmites are about.01 inches (250 to 300 microns) in length and have translucent bodies, so they are not visible to the unaided eye.
Dustmites are the leading source of allergens in the home, and their prime breeding ground is right under your nose.
Humans are not allergic to mites but to the protein in their fecal pellets and the body parts of dead mites, which are small enough to become airborne.
Dustmites are less than 1/2 millimeter long (approximately 10 could fit on the period at the end of this sentence).
Mites require moisture in their environment, and it is the most important factor in determining their survival and growth.
Feeds |
Contact