Asthma in the United States has increased in prevalence since the 1990s, which coincides with the increase of indoor activity. Since that time, there has been a 90% increase in the time that individuals spend indoors. Researchers are particularly interested in the relationship between asthma and indoor allergens. It has been shown that when atopic children are exposed to dust mite allergens, their risk for asthma increases. House dust mite allergy is the most common cause of allergic sensitization that afflicts asthmatics. In North and South America, Europe, south east Asia, and Australasia, up to 85% of individuals are allergic to dust mites.
About 10-15% of individuals in the Western world are asthmatic, and asthma is an allergy. An allergy can either lead to immunity, in which case it is protective, or it can lead to tissue damage and other adverse reactions that characterize immunological hypersensitivity. Likewise, allergenicity is the ability to produce an allergic sensitization. The ability of a house dust mite, or an allergen, to produce IgE is a measure of its allergenicity and this shows that the immune system has been altered to the allergic state.
The symptoms of dust mite allergy include sneezing, itchy nose, postnasal drip (a flow of mucus behind your nose and into your throat), stuffy nose, cough, red, itchy or watery eyes, runny nose, and itchy mouth or throat. Dust mite allergy may also trigger asthma, and in these cases, additional symptoms may appear. People who have had their asthma triggered by dust mites will have a difficulty of breathing, pain or tightness of chest, wheezing, whistling sound when breathing, and shortness of breath, coughing or wheezing which causes trouble sleeping.
Dust allergies occur because of particles from house dust mites, pollen, mold, animal particles (such as fur, feathers, hair, urine, saliva, and feces) that are usually too small for the naked eye to see. These components, found in dust, are too small for the eye to see. When it comes to dust mite allergies, it’s usually the dust mite’s feces that cause the allergies, rather than the dust mite itself. The aforementioned components of dust are a major problem for individuals with respiratory problems, such as asthma, eczema, and allergic rhinitis.
Allergic reactions occur when sensitization to house dust mite occurs. It is the most frequent cause of IgE-mediated allergies all over the world. The cause of allergic reactions to dust mites is mediated by the immune system. In addition, the IgE response to house dust mite allergens tends to begin early in life and this persists until adulthood. This type of allergy is usually persistent and is referred to a perennial disease since house dust mite allergens are present all year round. The problem with the fact that it is a disease that occurs all year round is that the exposure is continuous, which makes the inflammation chronic. In particular, the chronic exposure to allergens causes nasal obstruction. Nasal obstruction is the most bothersome clinical manifestation of the disease.
There are a number of risk factors for developing dust allergies. There are genetic and environmental factors. The control measures that are present in the home may account for the environmental factors that determine whether a person develops dust allergies or not. House dust is a variable mixture, and it varies according to the household and the region. It also contains various allergenic substances and consists primarily of allergens from mites and secondarily of allergens from animals, humans, and domestic insects. It also contains the endotoxins of gram-negative bacteria. This endotoxin is a potent substance that encourages inflammation in the body and is commonly found in house dust. Exposure to this substance will induce inflammation in the airways by constricting the airways and irritating the mucus membranes. Thus, houses that are dusty are risk factors for developing dust allergies.
The presence of house dust mites is another risk factor. House dust mites are usually the most common causes of allergies for asthma and allergic rhinitis. These insects are associated with bedding products, curtains, carpets, and fabrics. Increased sensitivity to house dust mites is related to persistent allergic rhinitis.
Another risk factor is the ownership of pets. Owning pets was found to increase the sensitization to allergens. It was found that the prevalence of asthma, skin allergy, and rhinitis was more common in households with animals compared to those without. The reason behind this is that the secretory proteins from pets cause severe hypersensitivity reactions. Allergies to animals are manifested by allergic rhinitis and asthma.
The genetic factors for developing dust allergy is having a first-degree relative that is asthmatic or has dust allergy as well. Having several first-degree relatives who have dust allergy is also a risk factor. Aside from this, living in areas where there is a high air pollution density may also be a risk factor, although this has not yet been proven.
Complications can arise any time that a person is exposed to allergens. Complications can range from mild to severe, life-threatening occurrences. Mild allergic complications are irritating but they are not life-threatening in most cases. Inflammation of the nasal passages or rhinitis is common, as is sinusitis, or inflammation of the sinuses.
The most severe complication arising from dust allergy is anaphylaxis, which can be life-threatening. Anaphylaxis most commonly arises as a response to food, drugs, latex, or insect stings. Emergency treatment is absolutely necessary in order to decrease the likelihood of death. Some signs of anaphylaxis may include a red rash that is accompanied by welts that are usually itchy. Another sign is that some parts of the body are swollen and the throat may be swollen as well. Chest tightness, trouble breathing, and trouble swallowing are other signs. Stomach cramping and a pale or red color to the body or face are other signs. In addition to these, patients who have had this reaction in the past should always carry epinephrine injections with them all the time. These injections will allow the symptoms to temporarily subside while medical help is sought and may potentially be life-saving.
In order to diagnose a dust allergy, a doctor will first conduct a physical examination on a patient and discuss symptoms. If the doctor believes that a patient has a dust allergy, then they may suggest a skin or blood test.
A Skin Prick Test may be advised. In a skin prick test, a small drop of the allergen is placed on the patient’s skin. Then, the doctor will prick the skin through the drop of the allergen. If the patient is allergic to the allergen, then he/she will develop redness in the area where the drop was placed, usually within 20 minutes. In this case, a red wheal may be seen. A wheal is a round area that looks like a hive. The larger the wheal, the more likely it is that the person is allergic to the allergen. A positive result on this test does not necessarily mean that the person has an allergy. Further tests need to be conducted.
Blood tests are usually helpful in determining whether a person has allergies. They may also be useful in children, who usually do not tolerate the skin prick test. The doctor will usually take a blood sample and take it to the laboratory for testing. The laboratory adds allergens to the blood sample and then measures a number of antibodies the blood produces in response to the allergens. The test is called Specific IgE Blood Testing.
The most important way to treat dust allergy is to avoid exposure to dust as much as possible by keeping surroundings clean. However, medicines may also be needed. Any use of medicine must be with the advice of a doctor.
Antihistamines are available as nose sprays, liquids, or pills. They act to relieve itchy eyes and nose. They also reduce nasal stuffiness. Nasal corticosteroids, on the other hand, are a type of nose spray. They act to reduce nasal swelling and to block allergic reactions. For allergic rhinitis, they are the most effective medicine because they reduce all types of symptoms, including nasal congestion. Leukotriene receptor antagonists block chemical messengers that are important mediators of allergic reactions. Cromolyn sodium is another nasal spray that blocks the release of chemicals that cause allergic reactions. Lastly, decongestants are available as drops, nose sprays, pills, and liquids. They relieve stuffiness as well. They can only be used for a short period of time. Oral decongestants have a few side effects. They make people sleepy and they also raise blood pressure.
Another option is to take allergy shots, which is also known as subcutaneous immunotherapy (SCIT), which provides people with complete relief from their allergies for one to three years. It is a series of shots that provide patients with progressively larger amounts of allergens. These shots provide long-lasting relief from allergies. In addition, people experience relief even after the shots stop.