What Causes Dust Mite Allergies?
Dust mites cause allergies by producing certain substances (allergens) that aggravate an overreaction by the immune system in some people. While allergies in general are thus a failure of the immune system to behave itself, there is no question that dust mite allergens are widespread and aggressive, making life miserable for many people.
Dust Mite Allergens
Both the North American dust mite, Dermatophagoides farinae, and the European dust mite, Dermatophagoides pteronyssinus, produce at least fifteen (15) different allergens each. These allergens are further classified by group numbers:
- Group 1 allergens (named after the species, such as “Der p 1,” “Der f 1”)
- Group 2 allergens (“Der p 2,” “Der f 2”)
- Group 3 allergens, group 4 allergens, and so forth
The most hostile of the allergens are those in Group 1 and Group 2, and those are also the allergens that nearly all dust-mite allergic people react to. Both of these allergen groups are associated with the digestive system of dust mites, and are present in large quantities in the fecal pellets defecated by the mites. When the fecal pellets become airborne and are inhaled by a hypersensitive person, an allergic reaction follows.
Group One Allergens
These allergens are proteins that have enzymatic properties. This makes them even more antagonistic to our immune systems. Most of us are familiar with the role of enzymes in digesting our food, and helping to catalyze chemical reactions in the laboratory. When Group One allergens are inhaled, they irritate the lining of bronchial tubes and stimulate an all-out blitz by our immune system. It is no wonder that someone can become asthmatic from exposure to such virulent allergens.
Group One allergens are not immortal, however, and they can become permanently deactivated by high temperatures and certain acidic compounds.
Group Two Allergens
These allergens are proteins which are apparently important to the mites for their own defense against foreign bacteria. Group Two allergens are likewise present mostly in fecal pellets and the bodies of dead mites. Exactly how they react with our immune system remains mostly a mystery, though they do actively bind with certain antibodies, like other dust mite allergens.
Group Two allergens are not deactivated by high temperatures.
Other Dust Mite Allergens
Much research remains to be done to assess the allergenic properties of those dust mite allergens that affect fewer allergic patients. Also important is learning how these more mysterious allergens interact with Group One and Group Two allergens, if they do so at all. Cross-reactivity between allergens can be as important as the actions of one allergen acting alone.