What Are the Signs of an Allergic Reaction to Dust Mites?

Dust mites are important allergens that induce allergic diseases such as asthma, allergic rhinitis and eczema. In recent years, studies have confirmed that dust mites are closely related to allergic diseases. According to surveys in many countries such as the United States, New Zealand and Australia, dust mites have been confirmed as important allergens in many countries. Hundreds of studies worldwide have confirmed the close relationship between dust mites and allergic diseases such as asthma.

Dust mite allergy

Western Medicine Name: Dust mite allergy
Disease site: skin

Main cause: dust mite
Contagious: Non-contagious

Overview of Dust Mite Allergies

Therefore, the World Health Organization (WHO) and the International Federation of Immunological Societies have jointly organized three international dust mite allergy work conferences, and drafted guidance documents on dust mite and allergic diseases, indicating the direction of future scientific research and main attacks. The scope has promoted the research and prevention of dust mites and allergic diseases. The World Health Organization (WHO) clearly states in its guidance document on immune desensitization that "desensitization is the only fundamental treatment that can completely treat allergic diseases."

The international authoritative organization for allergy research has also proposed that "the use of high-quality standardized desensitization agents should also use the best allergy treatment plan, including elimination of allergens, immune repair of patients, appropriate symptomatic medication for allergic inflammation, standardized desensitization Preparation of immunotherapy, referred to as "six in one six combination therapy" program.

In 2001, the WHO published a white paper stating that sublingual desensitization could completely replace traditional subcutaneous injection therapy. Sublingual desensitization therapy currently targets patients with allergies to dust mites and house dust mites. This method is safer to use, and patient compliance should be. Use method: Use different maintenance doses according to age. It can be taken under the tongue for 1-3 minutes at a relatively fixed time every day, which is convenient to use. Dose in increasing phase is divided into No. 1, 2, and 3. Maintenance dose is divided into No. 4 and No. 5. Generally under 14 years old is maintained with No. 4 and above 14 years old is maintained with No. 5.

Allergic rhinitis, allergic asthma, allergic conjunctivitis, allergic rash, allergic urticaria, allergic conjunctivitis caused by dust mites . The immunological parameters of patients before and after the sublingual dust mite immunotherapy have also changed. Because the sublingual mucosal tissue is thin, these Langerhans cells on the mucosal surface will catch the signal of the presence of allergens when they contact the antigen Allergen vaccines can be quickly absorbed, thus initiating a desensitization reaction. These include increased serum IgG4 levels and improved Th2 / Th1 cell ratios. Because it is administered sublingually, there are usually no serious adverse reactions such as anaphylactic shock. Very few patients occasionally have a mild rash or mild diarrhea, which can be recovered by stopping treatment or reducing the dose. The mechanism of sublingual desensitization treatment is because there are a large number of Langerhans cells in the sublingual mucosa. After absorbing a small amount of dust mite allergens, it can be processed into mite polypeptide information. By presenting them to Th0 cells, Th0 cells can Th1 cells transform, preventing the occurrence of allergic reactions.

Types and characteristics of dust mite allergic dust mites

Dust mites are tiny creatures, such as the size of a needle tip, which are invisible to the naked eye. There are a large number of dust mites growing in house dust, about 150 species, divided into two major ecological groups. One is house dust mites that breed in furniture and daily necessities (especially in bedding, sofas, carpets, sweaters, and cotton coats) and feed on human dander; the other is house dust mites that grow in storage such as food, food and herbs The warehouse dust mites in the warehouse are brought into the house by human life activities. The seasonal increase and decrease of dust mite density basically coincided with the increase and decrease in the number of emergency asthma patients, which also explained the correlation between dust mite and asthma.

Dust mite allergy breeding conditions

It mainly grows in bedding and clothing, such as cotton and its products, wool, feathers, and hemp, etc. It can also grow in large quantities in chemical fibers. Bedrooms have the most mattresses, pillows, rugs, and sofas, and can be found in clothes that are not often washed. Dust mite food is powdery material, such as human dander, flour, milk powder, and can also swallow plant pollen and mold spores and plant fiber.

Dust mites are globally distributed. Except that it is difficult to survive in the high-altitude areas above 2000 meters above sea level, they are found everywhere. Particularly suitable for growing in warm and humid areas, such as the coastal areas along the river in the east and south China. Breeding is slow in the initial stage, and then increases in geometric progression in the future, the number is amazing. At temperatures above 35 ° C, dust mites appear to stagnate. In temperate regions, the climate of cold winter and high summer is not suitable for dust mite growth. Therefore, there are two peaks of dust mite population in spring and autumn, and the density is higher in autumn than in spring. Breed in air-conditioned rooms throughout the year. Bedding and carpets in the bedroom are the most suitable breeding place for dust mites. There are less dust mites on the carpet in the living room, and more dust mites grow on the sofa.

Prevalence of dust mite allergies

Across the world, especially in Asia, Australia and Europe, the prevalence of dust mite allergies has approached or exceeded pollen allergies. Investigations in some areas have confirmed that the incidence of allergic to dust mites in asthmatic patients with younger age can be as high as 70%, and reports have also confirmed that more than 80% of asthmatic children and adolescents have a strong positive response to the dust mite allergen skin test. According to epidemiological surveys in Seoul and India, the incidence of asthma has increased in areas with high indoor dust mite densities; surveys in China in Shanghai have also obtained similar results. The study also found that in areas with a high incidence of dust mite allergy, the mean value of specific IgE in the serum of patients also increased significantly. According to surveys in two regions in France, the incidence of dust mite allergies is very low in areas with high altitudes and low dust mite densities. The above studies have confirmed that the incidence of asthma is closely related to the density of house dust mites, and there are certain regional differences. It is generally believed that the incidence is lower in cold, dry inland areas and higher altitudes, while it is higher in warm tropical areas and coastal areas. Global epidemiological surveys show that more than 80% of asthma patients are allergic to dust mites, especially in countries such as New Zealand and Australia. Due to humid air, indoor floors are generally covered with thick pure wool carpets, or sheepskin is used as baby sleeping pads, which is a large number of dust mites The favorable conditions provided by hygiene are the main reasons for the increase in the incidence of dust mite allergies and asthma in countries such as New Zealand and Australia.

Dust mite allergy

Dust mite allergy- specific immunodiagnosis

The diagnosis of dust mite allergy is mainly based on immunological tests. There are many clinical and in vitro immunological detection methods in clinical practice, including dust mite allergen skin test, serum dust mite specific IgE measurement, dust mite bronchial or nasal provocation test, mast cell degranulation test, eosinophil cation Determination of protein levels. Several methods commonly used in clinical practice are now highlighted.

Dust mite allergy skin test

At present, there are two kinds of skin test methods commonly used in clinic: intradermal test and skin prick test. Intradermal test is a traditional method of skin test, which is not commonly used at present. Skin prick test is currently the most commonly used test method. On the skin disinfected on the side of the forearm of the patient, a small drop of control solution, histamine, and dust mite infusion of 1: 100 concentration (millimeter grain size) can be arranged from top to bottom, and the spacing is not less than 3 cm. Use 3 disposable puncture needles to pierce the skin with the needle tip vertically in the middle of each drop to penetrate the liquid into the skin. After 2-3 minutes, wipe the liquid droplets left on the skin separately. Ruddy size judgment results.

Dust mite allergy bronchial or nasal mucosa challenge test

The dust mite bronchial provocation test is the basis for confirming the diagnosis of dust mite allergic asthma. You can judge whether the asthma patient is allergic to dust mite by observing the airway's response to inhaled dust mite. Because this test has the risk of inducing asthma attacks, the clinical Use less. Patients with allergic rhinitis suspected of having a dust mite allergy can undergo a nasal mucosal challenge test to help confirm the diagnosis.

Dust mite allergy serum dust mite specific antibody test

Patients with allergies to dust mites have increased serum-specific antibody levels. Dust mite-specific antibodies can be detected by ELISA or RAST methods. Clinically significant indicators include specific IgE, IgG, and IgA antibodies. Detection of specific antibody levels can help confirm the diagnosis of dust mite allergy and the degree of allergy, and can also be used as an indicator of clinical efficacy evaluation.

Dust Mite Allergy Dust Mite Desensitization Treatment

Desensitization therapy is an effective etiology treatment for dust mite allergies and has been commonly used by allergists, pediatricians, respiratory and rhinologists in many countries.

Dust mite allergy sublingual dust mite vaccine desensitization

The incidence of anaphylactic shock can be reduced by the sublingual or oral route. Sublingual desensitization is considered to be the most compliant dosage form. Because of its convenient administration, few side effects and reliable efficacy, sublingual desensitization has been widely used in Western Europe, Australia and other countries. Sublingual administration is generally free of age restrictions, and is easy to use. Just put a few drops of desensitization solution under the tongue, and it can be naturally absorbed in about 2 minutes. Asthma patients who are allergic to dust mites can reduce the number and duration of asthma attacks, reduce the inhaled dose of glucocorticoids, reduce airway responsiveness, and improve lung function after 3 to 9 months of sublingual dust mite immunotherapy. There were also changes in immunological indicators in the body before and after treatment, including an increase in serum IgG4 levels and an improvement in the ratio of Th2 / Th1 cells. Because it is administered sublingually, there are usually no serious adverse reactions such as anaphylactic shock. Very few patients occasionally have a mild rash or mild diarrhea, which can be recovered by stopping treatment or reducing the dose. The mechanism of sublingual desensitization treatment is because there are a large number of Langerhans cells in the sublingual mucosa. After absorbing a small amount of dust mite allergens, it can be processed into mite polypeptide information. By presenting them to Th0 cells, Th0 cells can Th1 cells transform, preventing the occurrence of allergic reactions. At present, the common trade name of the sublingual dust mite desensitization preparation in China is Chandi. Adults can increase the dose and concentration from Chandi No. 1 to No. 5 sublingually, and use Changdi No. 5 for maintenance treatment. Children from Chandi No. 1 to No. 4 were successively increased in dose and concentration under the tongue, and maintained with Changdi No. 4.

Dust mite allergy sublingual desensitization

The World Health Organization WHO clearly states in its guidance document on immune desensitization that "desensitization is the only fundamental treatment that can completely treat allergic diseases."

Allergic rhinitis, allergic asthma, allergic conjunctivitis, transient rash, allergic urticaria, allergic conjunctivitis caused by dust mites . The immunological parameters of patients before and after the sublingual dust mite immunotherapy have also changed. Because the sublingual mucosal tissue is thin, these Langerhans cells located on the mucosal surface will catch the signal of the presence of allergens when they contact the antigen. Allergen vaccines can be quickly absorbed, thus initiating a desensitization reaction. These include increased serum IgG4 levels and improved Th2 / Th1 cell ratios. Because it is administered sublingually, there are usually no serious adverse reactions such as anaphylactic shock. Very few patients occasionally have a mild rash or mild diarrhea, which can be recovered by stopping treatment or reducing the dose. The mechanism of sublingual desensitization treatment is because there are a large number of Langerhans cells in the sublingual mucosa. After absorbing a small amount of dust mite allergens, it can be processed into mite polypeptide information. By presenting them to Th0 cells, Th0 cells can Th1 cells transform, preventing the occurrence of allergic reactions.

Sublingual desensitization. Sublingual desensitization is the use of extracts of allergens dripping under the tongue to make the respiratory mucosa tolerant, thereby reducing or controlling allergic symptoms and reaching the purpose of desensitization treatment. Its clinical features are:

The world's fastest-growing desensitization treatment (ie, specific immunotherapy or immunotherapy) is in line with the rationalized treatment plan of symptomatic + cause recommended by the World Health Organization.

Treating both the symptoms and the root cause: radical treatment of allergic diseases, with significant effects and thorough desensitization; overcoming the limitations of traditional hormonal chemical drugs that treat symptomatically only at the onset of the disease. The degree of adverse reactions may produce some resistance.

High safety: Globally, no serious side effects have occurred in 30 years of use, and the long-term safety of medications for desensitization treatment has been ensured to the greatest extent; systemic serious adverse reactions (including anaphylactic shock, Even death), thereby reducing the psychological burden on medical staff and patients.

Development of dust mite allergy and desensitization treatment

In 1909, Noon succeeded in treating pollen rhinitis with autoimmune method, and opened a new era of immunotherapy. After more than half a century of practice, immunotherapy has shown certain clinical effects, but since the 1980s, as a result of several deaths in the United Kingdom due to the injection of immunotherapy preparations, the relevant government agencies have ordered a total ban on immunotherapy. .

In 1986, Scadding and Brostoff successfully used sublingual desensitization therapy (sublingual specific immunotherapy (SLIT)) for the first time to successfully treat allergic rhinitis, which revived hope for immunotherapy.

In 1992, the World Health Organization (WHO) confirmed through evidence-based medicine that immunotherapy for type I allergic diseases is effective, and believed that "if conditions are available, it should be applied as soon as possible", and immunotherapy has been re-promoted.

In 1993, the European Association of Allergy and Clinical Immunology (EAACI) pointed out that sublingual specific immunotherapy (SLIT) could be a potentially valuable treatment.

In 1998, the submission of the "WHO Allergen Immunotherapy Submission" pointed out that "desensitization treatment is the only possible cure for allergic diseases" and officially recommended the effectiveness and safety of sublingual specific immunotherapy. At present, the treatment of sublingual desensitization has been vigorously promoted in developed countries such as Europe and the United States, and the immunotherapy method of subcutaneous injection has gradually faded out of the mainstream medical scheme due to its potential harm.

In 2001, the Global Asthma Initiative (ARIA) confirmed the safety of high-dose allergen sublingual desensitization (at least 100 times the cumulative dose of subcutaneous immunotherapy) for children and adults.

In 2004, the World Health Organization recognized SLIT as one of the main treatments for treating allergic diseases such as allergic asthma and allergic rhinitis.

Dust mite allergy academician Zhong Nanshan

On July 8th, the world's first "World Allergy Day", Academician Zhong Nanshan, president of the Chinese Medical Association, pointed out that more than 200 million people in China suffer from allergic diseases, and desensitization has been recognized as an effective treatment.

Academician Zhong Nanshan introduced that currently 22% of the world's population suffers from allergic diseases such as allergic rhinitis, asthma, eczema, and it is increasing 23 times every 10 years. It is expected that in 2010, it will reach 40% of the global population. By analogy, more than 200 million people in our country are suffering from allergic diseases, which deserves attention.

The antigen that induces an allergic reaction is called an allergen. Allergens are a necessary condition for allergies to occur. Commonly, there are 2000-3000 kinds of antigens that cause allergic reactions, and medical literature records close to 20,000 kinds. They cause allergies to the body through inhalation, ingestion, injection or contact. The common allergens are as follows:

A. Inhaled allergens: such as pollen, catkins, dust, mites, animal dander, soot, paint, automobile exhaust, gas, cigarettes, etc.

B. Ingestion-type allergens: such as milk, eggs, fish and shrimp, beef and mutton, seafood, animal fats, alloproteins, alcohol, drugs, antibiotics, anti-inflammatory drugs, sesame oil, flavors, onions, ginger, garlic, and some vegetables and fruits Wait.

C, contact allergens: such as cold air, hot air, ultraviolet, radiation, cosmetics, shampoo, dishwashing liquid, hair dye, soap, chemical fiber supplies, plastic, metal jewelry (watches, necklaces, rings, earrings), bacteria , Mold, virus, parasite, etc.

D. Injectable allergens: such as penicillin, streptomycin, xenogeneic serum, etc.

E. Self-tissue antigens: self-tissue antigens that cause changes in structure or composition due to the effects of biological and physical and chemical factors such as psychiatric stress, work stress, microbial infection, ionizing radiation, and burns, and self-hidden antigens released by trauma or infection Can also be an allergen.

The most effective measure to treat refractory allergies is to find allergens (allergens), but to accurately find the pathogenic factor among 20,000 different inducers is like looking for a needle in the sea. The latest authoritative experiments confirm that the amount of free radicals in allergic people is much higher than that in non-allergic people! Free radical damage to the human immune system is the basis for the formation of allergies, and it will also directly oxidize the human mast cells and basophils, causing the cell membrane to rupture and release histamine, resulting in an allergic reaction. Therefore, improving the allergy will eliminate free radicals.

Free radicals come from two sources: first, they are constantly produced during the body's own oxidative metabolism; second, environmental pollution, radiation, and bad living habits, etc., can also continuously generate free radicals. Free radicals can be called the source of all evils. The aging of the human body and the occurrence of many diseases are closely related to it. Lipid peroxides formed by free radicals can damage biofilms, damage cells, hinder normal metabolism, accelerate aging, and can cause immune imbalances, allergies, refractory dermatitis, rhinitis, conjunctivitis, asthma, eczema, hypertension , Myocardial infarction, diabetes, hepatitis, gout, nephritis, cataract and many other diseases.

In the current hospital tests, it is far from comprehensive to check only 50-100 allergens, but we can completely change our allergies through the Guangpu desensitization factor series.

The World Health Organization WHO clearly states in its guidance document on immunodesensitization treatment that "immunodesensitization treatment is the only fundamental treatment that can completely treat allergic diseases."

The international authoritative organization for allergy research has also proposed that "the use of high-quality standardized desensitization agents should also use the best allergy treatment plan, including elimination of allergens, immune repair of patients, appropriate symptomatic medication for allergic inflammation, standardized desensitization Preparation immunotherapy, referred to as "four-in-one quadruple therapy" program.

Dust mite allergy desensitization precautions

1. Long duration. Desensitization therapy takes a long time, sublingual desensitization therapy is usually two years, and subcutaneous desensitization therapy is at least three years. Subcutaneous injection desensitization therapy is once a week for the first half of the year, and then once every two weeks to the last month. Otherwise, it will be exhausted or it will take more time to treat allergic rhinitis.

2. Intolerance to drug concentration. Sublingual desensitization is a daily medication with mild intolerance. Subcutaneous injection desensitization is the injection of allergens into patients to make them tolerant, so there may be systemic reactions. Patients should stay in the hospital for observation half an hour after the injection, in order to have emergency situations such as shortness of breath, redness and itching of the skin as soon as possible deal with.

3. Individuals with allergies are quite different, with a clinical effective rate of 80%. Desensitization therapy is not a 100% cure for allergic rhinitis, but it is currently the only cure.

4. If you have allergic symptoms during desensitization treatment, you need to cooperate with the drug treatment to control the symptoms in time. If the desensitization therapy is stable, you only need to do injection treatment. If the weather changes suddenly or you have a cold, you should take medicine and local treatment.

5, the onset is relatively slow. Since desensitization treatment needs to last at least two years, the general onset time is 3-9 months.

Dust mite allergy routine subcutaneous injection desensitization

Subcutaneous injection with allergen infusion is a traditional desensitization treatment. The dose is gradually increased from low concentration to high concentration, so that the patient reaches the maximum tolerated amount and maintains injection desensitization for three years. Since the allergenicity of dust mites is 1-2 times stronger than that of other allergens, the dose for dust mite desensitization treatment is generally smaller. Clinically, the concentration is often diluted to 10-6-10-10 according to the severity of allergies to dust mites. The injection is started from 0.1 ml, twice a week, and the dose is increased by 0.1 ml each time. Starting from 0.1 ml, twice a week, the increasing dose is 0.1 ml until 1 ml, and then the concentration is increased accordingly, each concentration is increased from 0.1 ml to 1 ml to 10-2, the concentration at this stage. Immunotherapy is called the escalation phase, and then enters the maintenance phase. The maintenance concentration is 10-2, twice a week, and the maintenance dose is 0.5ml each time. Should be maintained for 2-3 years. After entering the maintenance phase, the treatment symptoms are stable, the dosage of each injection is unchanged, and the interval can be gradually extended to once a week, once every two weeks, once a month until the drug is discontinued.

Dust mite allergy prevention measures

Dust mites are mainly born in bedrooms, including bedding, sofas, carpets and curtains, so the prevention of dust mites should be mainly in the following areas.

1. All beddings include mattresses, and professional bedding cleaning services are implemented regularly. Using professional cotton anti-mite bedding with stomata less than 10 microns for wrapping to reduce allergen concentration can effectively alleviate the allergic symptoms of dust mites.

2. All washable bedding, such as bedspreads, quilts, blankets, and pillowcases, should be scalded with hot water at 55 degrees or higher for 10-20 minutes every 7-10 days to kill dust mites. Use 100 degrees of hot water Can cause allergenic protein to denature, the effect is better.

3, bedding that is difficult to wash, such as cotton, should often be exposed to the sun and beat, and dust mites, dust and dandruff should be beaten out.

4. According to economic conditions, all bedding should be replaced once every 1-3 years.

5. Remove the carpet, sofa, woolen cloth and flannel ornaments in the bedroom.

6. Reduce the humidity in the home. If possible, use a dehumidifier. And do not use the radiator to dry or dry clothes indoors.

7. Increase ventilation to remove allergens, such as opening windows.

8. Reduce possible habitat by removing heavy carpets, thick curtains, old fluffy toys and upholstered furniture.

9. Before cleaning pillows and fluffy toys, freezing them for 24 hours can effectively kill dust mites.

10. Do not wear pajamas out of the bedroom. Many invisible allergens, such as those of cats and dogs, may run onto the body and return to the bedroom to cause problems.

11. When cleaning, keep the windows open to allow air to circulate and allow dust to run outdoors.

12, the exhaust of the clothes dryer must be installed outside the house to ensure that dust mites will not remain in the room.

13. Use mite predators to kill mites