House dust mites (HDM, or simply dust mites) are various species of acariform mites belonging to the family Pyroglyphidae that are found in association with dust in dwellings. [3] They are known for causing allergies.
The currently known species are: [4]
The dust mites are cosmopolitan members of the mite family Pyroglyphidae.
House dust mites, due to their very small size and translucent bodies, are barely visible to the unaided eye. [5] A typical house dust mite measures 0.2–0.3 mm in length. [6] The body of the house dust mite has a striated cuticle.[ citation needed ]
House dust mite faecal pellets range from 10 to 40 μm. [1]
Dust mites feed on skin flakes from humans and other animals, and on some mold. Dermatophagoides farinae fungal food choices in 16 tested species commonly found in homes was observed in vitro to be Alternaria alternata , Cladosporium sphaerospermum , and Wallemia sebi , and they disliked Penicillium chrysogenum , Aspergillus versicolor , and Stachybotrys chartarum . [7]
The predators of dust mites are other allergenic mites ( Cheyletiella ), silverfish and pseudoscorpions. [8]
The average life cycle for a house dust mite is 65–100 days. [9] A mated female house dust mite can live up to 70 days, laying 60 to 100 eggs in the last five weeks of her life. In a 10-week life span, a house dust mite will produce approximately 2,000 fecal particles and an even larger number of partially digested enzyme-covered dust particles. [10]
Dust mites are found worldwide, but are more common in humid regions. [11] The species Blomia tropicalis is typically found only in tropical or subtropical regions. [12] Detectable dust mite allergen was found in the beds of about 84% of surveyed United States homes. [13] In Europe, detectable Der p 1 or Der f 1 allergen was found in 68% of surveyed homes. [14]
House dust mite antigens are strongly associated with asthma development and severity; they are estimated to contribute to 60-90% of cases. [15]
Tropomyosin, the major allergen in dust mites, is also responsible for shellfish allergy. [16] [17]
Dermatophagoides spp. can cause oral mite anaphylaxis (AKA pancake syndrome) when found in flour. [18] [19]
Allergies, also known as allergic diseases, are various conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic dermatitis, allergic asthma, and anaphylaxis. Symptoms may include red eyes, an itchy rash, sneezing, coughing, a runny nose, shortness of breath, or swelling. Note that food intolerances and food poisoning are separate conditions.
An allergen is a type of antigen that produces an abnormally vigorous immune response in which the immune system fights off a perceived threat that would otherwise be harmless to the body. Such reactions are called allergies.
A food allergy is an abnormal immune response to food. The symptoms of the allergic reaction may range from mild to severe. They may include itchiness, swelling of the tongue, vomiting, diarrhea, hives, trouble breathing, or low blood pressure. This typically occurs within minutes to several hours of exposure. When the symptoms are severe, it is known as anaphylaxis. A food intolerance and food poisoning are separate conditions, not due to an immune response.
Allergen immunotherapy, also known as desensitization or hypo-sensitization, is a medical treatment for environmental allergies and asthma. Immunotherapy involves exposing people to larger and larger amounts of allergens in an attempt to change the immune system's response.
Atopy is the tendency to produce an exaggerated immunoglobulin E (IgE) immune response to otherwise harmless substances in the environment. Allergic diseases are clinical manifestations of such inappropriate, atopic responses.
Peanut allergy is a type of food allergy to peanuts. It is different from tree nut allergies, because peanuts are legumes and not true nuts. Physical symptoms of allergic reaction can include itchiness, hives, swelling, eczema, sneezing, asthma attack, abdominal pain, drop in blood pressure, diarrhea, and cardiac arrest. Anaphylaxis may occur. Those with a history of asthma are more likely to be severely affected.
Milk allergy is an adverse immune reaction to one or more proteins in cow's milk. Symptoms may take hours to days to manifest, with symptoms including atopic dermatitis, inflammation of the esophagus, enteropathy involving the small intestine and proctocolitis involving the rectum and colon. However, rapid anaphylaxis is possible, a potentially life-threatening condition that requires treatment with epinephrine, among other measures.
Egg allergy is an immune hypersensitivity to proteins found in chicken eggs, and possibly goose, duck, or turkey eggs. Symptoms can be either rapid or gradual in onset. The latter can take hours to days to appear. The former may include anaphylaxis, a potentially life-threatening condition which requires treatment with epinephrine. Other presentations may include atopic dermatitis or inflammation of the esophagus.
Skin allergy testing comprises a range of methods for medical diagnosis of allergies that attempts to provoke a small, controlled, allergic response.
Pyroglyphidae is a family of non-parasitic mites. It includes the house dust mite that live in human dwellings, many species that live in the burrows and nests of other animals, and some pests of dried products stored in humid conditions.
The MD-2-related lipid-recognition (ML) domain is implicated in lipid recognition, particularly in the recognition of pathogen related products. It has an immunoglobulin-like beta-sandwich fold similar to that of immunoglobulin E-set domains. This domain is present in the following proteins:
Peptidase 1 (mite) (EC 3.4.22.65), also known as endopeptidase 1 (mite), is an enzyme found in various species of mites. This enzyme exhibits cysteine protease activity with broad endopeptidase specificity.
Aspergillus penicillioides is a species of fungus in the genus Aspergillus, and is among the most xerophilic fungi.
Oral mite anaphylaxis (OMA), also known as pancake syndrome, is a disease in which a person gets symptoms after eating food contaminated with particular mites. The disease name comes from reports of people becoming ill after eating pancakes made from contaminated wheat or corn (maize) flour.
Exercise-induced anaphylaxis is a rare condition in which anaphylaxis, a serious or life-threatening allergic response, is brought on by physical activity. Approximately 5–15% of all reported cases of anaphylaxis are thought to be exercise-induced.
Fish allergy is an immune hypersensitivity to proteins found in fish. Symptoms can be either rapid or gradual in onset. The latter can take hours to days to appear. The former may include anaphylaxis, a potentially life-threatening condition which requires treatment with epinephrine. Other presentations may include atopic dermatitis or inflammation of the esophagus. Fish is one of the eight common food allergens which are responsible for 90% of allergic reactions to foods: cow's milk, eggs, wheat, shellfish, peanuts, tree nuts, fish, and soy beans.
Dust mite allergy, also known as house dust allergy, is a sensitization and allergic reaction to the droppings of house dust mites. The allergy is common and can trigger allergic reactions such as asthma, eczema or itching. The mite's gut contains potent digestive enzymes 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.
Shellfish allergy is among the most common food allergies. "Shellfish" is a colloquial and fisheries term for aquatic invertebrates used as food, including various species of molluscs such as clams, mussels, oysters and scallops, crustaceans such as shrimp, lobsters and crabs, and cephalopods such as squid and octopus. Shellfish allergy is an immune hypersensitivity to proteins found in shellfish. Symptoms can be either rapid or gradual in onset. The latter can take hours to days to appear. The former may include anaphylaxis, a potentially life-threatening condition which requires treatment with epinephrine. Other presentations may include atopic dermatitis or inflammation of the esophagus. Shellfish is one of the eight common food allergens, responsible for 90% of allergic reactions to foods: cow's milk, eggs, wheat, shellfish, peanuts, tree nuts, fish, and soy beans.
A food allergy to sesame seeds has prevalence estimates in the range of 0.1–0.2% of the general population, and are higher in the Middle East and other countries where sesame seeds are used in traditional foods. Reporting of sesame seed allergy has increased in the 21st century, either due to a true increase from exposure to more sesame foods or due to an increase in awareness. Increasing sesame allergy rates have induced more countries to regulate food labels to identify sesame ingredients in products and the potential for allergy. In the United States, sesame became the ninth food allergen with mandatory labeling, effective 1 January 2023.