1. What is an allergic disease?
An allergic reaction, also known as a metamorphosis, is an abnormal reaction of the body to one or more substances that are not harmful to most people. The main reason is that the body of the allergic reaction patient produces too much of a special antibody called immunoglobulin E (IgE), which can react with the allergenic substances (allergens) in the environment and stimulate the body to produce and release certain excessive chemicals, and then produce various symptoms, such as: nasal symptoms (nasal itching, sneezing, running snot, nasal congestion, etc.), lower respiratory symptoms (shortness of breath, chest tightness, coughing, wheezing, etc.), and eye symptoms (eye problems). (shortness of breath, chest tightness, coughing, wheezing, etc.), eye symptoms (itchy eyes, tearing, etc.), and skin symptoms (hives, eczema, etc.).
2.What are the allergic diseases?
Allergic diseases are one of the common diseases that affect people’s quality of life and may even be life-threatening. Common allergic diseases include asthma, allergic rhinitis, allergic skin diseases, drug allergy, food allergy, anaphylaxis, etc.
Nose: nasal itching, sneezing, clear watery snot, nasal congestion.
Lungs: chest tightness, shortness of breath, cough, wheezing.
Eyes: itchy eyes, tearing, conjunctival congestion.
Skin: red rash with itchy skin, white or red wind clumps with itchy skin.
Digestive tract: stomach cramps, vomiting, diarrhea.
3.What are antigens?
An irritant that can cause an immune or allergic reaction in the body. It is foreign to the body and is an inseparable pair with the composition of the antibodies it triggers.
Antigens have three basic characteristics.
First, immunogenicity: antigens can cause an immune response when they enter the body, that is, they stimulate the body’s immune system and produce antibodies or sensitized lymphocytes.
Second, immunoreactivity: the antigen can produce a specific reaction with the resulting antibody or sensitized lymphocytes.
Third, immune tolerance: when the immune function is not yet mature or immune function is suppressed, the antigen entering the body can not cause an immune response.
Antigen is a macromolecular substance, generally protein or protein-containing complex, but in addition to protein, lipids or polysaccharides can also participate in the metabolic reaction as semi-antigens.
Antigens can be divided into two categories: complete antigens and semi-antigens. Most proteins and bacteria and viruses are macromolecules that are immunogenic and immunoreactive in their own right, so they are called complete antigens. Polysaccharide lipids and certain chemicals are small molecules, they are only immunoreactive but not immunogenic, so they are incomplete antigens, also known as semi-antigens, and semi-antigens only have immunogenicity when combined with proteins, to function as complete antigens.4 What are the common allergens?
Antigens that induce allergic reactions are called allergens. There are hundreds of antigenic substances that cause allergic reactions and they sensitize the body by inhalation, ingestion, injection or contact.
Inhaled allergens: mites, pollen, willow, dust, animal dander, oil smoke, paint, car exhaust, gas, cigarettes, etc.
Ingested allergens: certain drugs, food, especially fish, eggs, milk and nuts, etc.
Contact allergens: cold air, hot air, ultraviolet light, radiation, cosmetics, shampoo, hair dye, detergent, chemical fiber products, metal jewelry (watches, necklaces, rings), bacteria, mold, viruses, parasites, etc.
Injectable allergens: penicillin, streptomycin, heterologous serum, etc.
Other allergens: mental tension, work stress, infection by microorganisms, ionizing radiation, burns and other biological and physical and chemical factors that change the structure or composition of their own tissue antigens, etc.
5.Fungi.
Fungi are divided into two categories, yeasts and molds. The main allergenic human body is mold. Therefore, sometimes fungi and molds can be used interchangeably.
Airborne fungi are common allergens that induce perennial allergy, and are usually divided into two categories: outdoor fungi and indoor fungi.
Outdoor fungi.
The most common outdoor fungi are Streptomyces interrogans and Dictyostelium, followed by Rhizopus and Fusarium spp. In the outdoor, most fungi in 18 to 320C and greater than 65% humidity environment to grow well (the rainy season in the south of China, the northern wheat harvest before and after, is the best period of mold growth). They grow on plants and in decaying vegetation, also from fertile soil and dead grass, and the spores they send out are dispersed in the air and are a major part of asthma triggers.
Ways to reduce exposure to outdoor fungi.
Patients who are allergic to outdoor fungi should stay indoors as much as possible during the season of attack.
Indoor fungi.
The most important of indoor fungi are Aspergillus spp. and Penicillium spp. (which are the green molds that emit from damp basements). Dark, damp, poorly ventilated rooms, especially basements are ideal places for fungal growth, followed by washrooms and kitchens, air conditioners and humidifiers can also be places for mold growth.
Ways to reduce exposure to indoor fungus.
Living rooms, washrooms, kitchens should be ventilated and dry; careful use of humidifiers and air conditioners and frequent cleaning; remove carpets as much as possible.
6. Pollen.
Trees, pasture and weeds three major types of plant pollen is spread by the wind, these pollen scattered in the air is an important source of airborne allergens, these pollen without fragrance, large number, light weight, wide spread area, can be with the wind to high altitude and distant fields and towns, is the main allergens that induce allergic diseases. The air is pollen particles can be as many as 800 per cubic meter on warm sunny days, generally the highest number before storms, and can be greatly reduced on rainy days.
Pollen and seasonality.
In spring, wind-borne pollen mostly originates from trees, such as: pine, cypress, poplar, elm, willow, birch, etc. Late spring and early summer wind-borne pollen mostly comes from pasture. Late summer and early autumn wind-borne pollen mostly comes from weed species. In our country to artemisia sin common, followed by quinoa, ragweed, grass, etc.. These grass pollen drifting time is long, causing heavier symptoms and longer duration of symptoms. 90% of hay fever is caused by pollen in summer and autumn. Take Artemisia as an example, 13 pollen particles per cubic meter of air can cause clinical symptoms.
Insect-borne flowers.
Insect-borne flowers are generally ornamental flowers, and their pollen can also cause allergic diseases. Common ones are chrysanthemums, incense flowers, dahlias, etc.
Ways to reduce exposure to pollen allergens.
During the pollen dispersal season, reduce outdoor activities as much as possible, stay indoors, close doors and windows; if you go out, it is best to wear a mask or stay in a closed car.
Be sure to close windows before rain and when it is windy.
Try to stay away from clearly allergenic insect-borne flowers.
7. House dust and dust mites.
The most important inducer of allergic diseases in house dust belongs to dust mites. In China, 70% to 80% of allergic disease patients are allergic to dust mites. House dust mites and dust mites are the most common and important types of house dust. There are cross-allergens with them, such as Méneris mites and storage mites.
House dust mites under the microscope are about 400 to 500µm long, and dust mites are about 300 to 400µm long, and are small spider-like animals with eight legs. They grow and reproduce by eating up to 50 million skin scales shed per person per day. Each gram of house dust can contain up to 1350 dust mites, and the most common place where dust mites live – the bed – can contain two million dust mites.
Factors affecting mites in house dust.
Dust mites grow best in warm (18-30°C) and humid (RH 70%-80%) seasons. But even in extremely dry conditions, it takes several months for mites deep in sofas, carpets, or mattresses to die and for the level of allergens in the home to drop.
Dust mites and the seasons.
Dust mites are a perennial allergen, but levels of dust mite allergens in the living room are highest in the fall, so infants born in the fall have a younger age of onset of asthma, and those sensitized to dust mites tend to get sicker in the fall.
Ways to reduce exposure to dust mite allergens.
(1) Wash bedspreads, sheets, pillowcases and other bed knitted products regularly, preferably with hot water at 60℃. You can also use anti-mite bedspreads and pillowcases if you have the conditions.
(2) Flooring: Do not use carpets or upholstery, but should use wood, tile or wooden flooring.
(3) Room: The room must be cleaned regularly, because the cleaning process is bound to make a large number of dust mites floating in the air, so dust mite allergic people when cleaning, it is best to put on a dust mask or take shelter outside the house. You should always use a wet cloth to wipe the dust or use a powerful vacuum cleaner with a filter.
(4) Use air conditioners or dehumidifiers to keep the room dry; use air filters and regularly clean and replace the filters.
8.What is the skin prick test?
The skin prick test is performed by placing a small amount of highly purified allergen liquid on the patient’s forearm and then gently pricking the skin surface with a prick needle. If the patient is allergic to the allergen, a red swelling similar to a mosquito bite will appear at the site of the prick within 15 minutes. The skin prick test is now recognized as the most convenient, economical, safe and effective allergen diagnosis method in European countries and the United States, with the advantages of high safety and sensitivity, painless to the patient, just like a mosquito bite, and both the patient and the doctor can immediately know the test results.
9.What is the specific immunoglobulin E test?
Immunoglobulin E test, is to take a patient’s blood sample, using chemical methods, to detect the specific immunoglobulin E content produced in the patient’s body, it has the advantage of not being affected by the patient taking antihistamines, the disadvantage is that the sensitivity is lower than the skin prick method, the patient can only know the results after a few days, and the cost of the test is more expensive than the skin prick test.
10.What is the relationship between allergic rhinitis and allergic asthma?
Allergic rhinitis and allergic asthma are both typical conditions of allergic respiratory diseases, both characterized by cellular infiltration, mucosal swelling, exudation and increased secretion, etc. They are often stimulated by the same allergens and are mostly seen in people with a family history of allergy. Therefore, it is believed that allergic rhinitis and bronchial asthma are different manifestations of the same disease, if the lesion is limited to the upper respiratory tract, i.e., allergic rhinitis, allergic sinusitis, etc.; if the lesion causes spasm of bronchial smooth muscle, the small bronchial respiratory resistance increases, and the allergic rhinitis is caused by allergic rhinitis. If the lesion causes smooth muscle spasm of the bronchial tubes, the respiratory resistance of the small bronchial tubes increases, then it appears as asthma. But why do some patients have only allergic rhinitis or bronchial asthma, while others have both? This may be related to the genetic quality of the patient. It is worth noting that about 30% of patients with allergic rhinitis will develop bronchial asthma, while most patients will have asthma symptoms significantly reduced when the symptoms of allergic rhinitis are eliminated. According to international studies, early standardized allergen immunotherapy for allergic rhinitis in children can prevent 75% of rhinitis patients from developing asthma.
11.How to diagnose allergic diseases?
From the viewpoint of modern allergology, a complete diagnosis of allergic diseases should include three parts, namely a thorough medical history, in vivo tests and in vitro tests.
The first step in the diagnosis of allergic diseases is to make a diagnosis and differential diagnosis of the disease and to determine initially what kind of disease is being suffered from: whether it is allergic rhinitis or sinusitis, whether it is combined with asthma or nasal polyps; whether it is bronchial asthma or chronic bronchitis, whether it is combined with emphysema, and so on. In addition to this, allergens need to be examined accordingly, that is, to determine which substances the patient is allergic to, which is known as allergen-specific diagnosis of allergic diseases. Allergen-specific diagnosis is at the heart of allergology.
The test methods can be divided into in vivo and in vitro tests. The in vivo test is to apply allergens to the human body through skin testing or prick and other methods to observe the human body’s reaction to allergens and determine whether the patient is allergic to these allergens; the in vitro test is to take the patient’s blood or other body fluids for in vitro testing, and the allergens are not directly applied to the human body.
12.How to treat allergic respiratory disease?
To effectively treat allergic respiratory disease, three aspects must be addressed simultaneously.
First, avoid contact with and remove the allergen. After the allergen is identified by skin prick test or specific immunoglobulin E test, the patient should actively avoid contact with the allergen and take measures to reduce or even remove the allergen.
Second, use appropriate medication: This is a non-targeted treatment that aims to help patients temporarily control their condition, while reducing discomfort and improving allergic reactions, such as anti-inflammatory, etc. However, it should be noted that medication generally cannot achieve a cure, and to achieve the best results, patients should avoid contact with allergens during medication. Finally, standardized allergen immunotherapy should be received as soon as possible.
13. Avoidance of atopic allergy triggers.
In terms of the prevention and treatment strategy for allergic diseases, the most fundamental and important link is to avoid allergen exposure. From the clinical practice summed up the four key words DD “avoid”, “avoid”, “alternative”, “move”.
”Avoid”, that is, avoid contact with all suspected or known allergic triggers, including all allergenic inhalation, ingestion or contact.
”Avoidance” means avoiding all suspected or known allergic substances, mainly referring to food and drugs. For example, if the patient can induce hives every time he/she eats shrimp or crab, he/she should try to avoid the foods listed above.
”If the patient is allergic to a certain drug or food, but cannot stop using it for various reasons, try to find a drug or food with similar effects and no allergy to the patient. For example, if an infant is allergic to cow’s milk, which can cause severe eczema, you can replace cow’s milk with human milk, goat’s milk or soy milk and other foods to which the infant is not allergic.
”Removal” means that certain allergens known to be in frequent contact with the patient should be removed from the patient’s living environment as soon as they are identified. For example, if the patient is allergic to the paint of a new piece of furniture in the room, it should be removed from the patient’s living environment as soon as possible.
14.What is specific immunotherapy?
Specific immunotherapy (also known as standardized desensitization) is the only allopathic treatment recommended by the World Health Organization and the Global Academy of Allergy, Asthma and Immunology that can change the immune mechanism of allergic patients. This method involves giving standardized desensitization vaccines to allergic patients over a period of time, starting with a low dose and increasing the dose over a certain period of time to reach the optimal maintenance dose for the patient in about 3 months, and then maintaining the treatment at a frequency of 1-2 monthly injections (depending on the progress of the treatment) for a certain period of time (usually 3-5 years). After a certain period of time (usually 3-5 years), the patient will not develop allergic symptoms even if he/she is exposed to the allergen in his/her life again.
Role of specific immunotherapy.
Reduces or disappears allergy symptoms, reduces the frequency of rhinitis and asthma attacks, and improves the quality of life.
Prevent the development of allergic rhinitis into asthma.
Maintain long-term efficacy even after standardized desensitization treatment is completed.
Reduce the use of hormones and other symptomatic drugs, effectively avoiding the adverse reactions caused by long-term medication, especially the possible effects on the growth and development of children.
Improves allergic constitution and interrupts the development of new allergies
Reduce the total cost of treatment and reduce the financial burden on the family.
Who is suitable to receive immunotherapy (desensitization)?
Those who have a clear allergen but cannot completely avoid exposure (e.g. mite allergy)
Antihistamines and topical medications are not sufficient to control symptoms.
Do not wish to be treated with medication.
Have been on medication for a long time and have experienced severe drug reactions.
Who is not a good candidate for immunotherapy (desensitization)?
Patients should not undergo desensitization therapy if they are in a severe immunopathological state or have a malignancy.
Adrenaline is contraindicated: for example, immunotherapy should not be used in coronary artery disease, severe arterial hypertension and when treated with beta-blockers.
Lack of collaboration and severe psychological disorders. Immunotherapy in young children (children younger than 5 years) should be carried out only by specialists who have specialized in the treatment of allergic reactions in specific age groups.
Immunotherapy should not be initiated during pregnancy. In already initiated and well-tolerated immunotherapy, the risk of anaphylaxis is low, at which point, if pregnancy occurs, treatment can be continued.
Patients with FEV1 < 80% of the expected value may have poorer clinical outcomes and more side effects from immunotherapy. Severe atopic dermatitis should be treated for the primary disease before starting immunotherapy.