what part of the dust mite contains the primary allergen
House dust mite The mite's gut contains potent digestive enzymes (notably Peptidase 1) that persist in their feces and are major inducers of allergic reactions such as wheezing. The mite's exoskeleton can also contribute to allergic reactions. Unlike scabies mites or skin follicle mites, house dust mites do not burrow under the skin and are not parasitic.[6]
Trombiculidae Trombiculid mites are found throughout the world. In Europe and North America, they tend to be more prevalent in the hot and humid regions. In the more temperate regions, they are found only during the summer (in French, harvest mites are called aoûtat because they are common in August[20]). In the United States, they are found mostly in the southeast, the south, and the Midwest. They are not present, or barely found, in far northern areas, high mountains, and deserts.[21] In the British Isles, the species Trombicula autumnalis is called harvest mites, in North America the species Trombicula alfreddugesi, and the species Trombicula (eutrombicula) hirsti which are found in Australia and are commonly called the scrub-itch mite.[22]