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Introduction
Introduction to urticaria Urticaria (urticaria), commonly known as rubella, is a limited edema reaction caused by the expansion of skin and mucosal small blood vessels and increased permeability. The clinical manifestations are rubella damage of varying sizes, which suddenly occurs, rapidly subsides, and itching is severe. After that, there are no traces left. There are many causes of urticaria, and patients should try to avoid contact predisposing factors in the prognosis. basic knowledge The proportion of illness: 0.3% Susceptible people: no special people Mode of infection: non-infectious Complications: diarrhea, shock, laryngeal edema
Cause
Urticaria cause
Food (15%):
Such as fish, shrimp, eggs, milk are the most common, followed by meat and certain plant foods, such as strawberries, cocoa, tomatoes, and other spoilage foods are broken down into peptides, basic peptides are histamine release, protein Foods are absorbed in the form of sputum or peptides before they are thoroughly digested, which can cause urticaria, which is more common in children. It may also be caused by differences in the permeability of the digestive tract mucosa of children, and the addition of pigments in food. , flavoring agents, preservatives, natural or synthetic substances in food can also cause urticaria.
Drugs (10%):
Can be divided into two categories, one is the formation of antigen-based drugs, such as penicillin, serum, vaccine, sulfonamide, furazolidone, etc., the other is histamine release agents, such as aspirin, morphine, codeine, pethidine, and more Colistin, vitamin B, quinine, hydrazine and the like.
Infection (10%):
Various infection factors can cause the disease, the most common are the virus and Staphylococcus aureus, followed by hepatitis, infectious mononucleosis and Coxsackie virus; parasitic infections, such as aphids, Hookworm, schistosomiasis, filarial, amoeba and malaria parasites; bacterial infections such as acute tonsillitis, alveolar abscess, sinusitis, impetigo, sepsis, etc.
Inhalation (15%):
Pollen, dust, animal dander, smoke, feathers, fungal spores, volatile chemicals (such as formaldehyde, acrolein, pyrethrum, cosmetics, etc.) and other airborne allergens.
Physical factors (19%):
Physical and mechanical stimuli such as cold, heat, sunlight, friction and pressure.
Visceral and systemic diseases (15%):
Such as rheumatic fever, rheumatoid arthritis, systemic lupus erythematosus, malignant tumor, hyperthyroidism, hyperlipidemia, endocrine changes (menstruation, pregnancy, menopause), infectious mononucleosis and chronic diseases such as cholecystitis, nephritis , diabetes, etc.
Animal and plant factors (15%):
Such as insect bites, poisonous burrs (such as caterpillars, beetles and moths scales into the skin) and contact with castor, wool and so on.
Mental factors (15%):
Mental stress or excitement, causing acetylcholine release after exercise.
Genetic factors (5%):
Some types of urticaria are genetically related, such as familial cold urticaria, hereditary familial urticaria syndrome.
Pathogenesis
There are two kinds of allergic and non-allergic:
Allergic
Most of them are type I allergic reactions, a few are type II and type III allergies, and type I allergic reactions are mediated by IgE, also known as IgE-dependent reactions. The mechanism is that the above allergens produce IgE-like antibodies in the body and are adsorbed around the blood vessels. Mast cells and blood-sequent basophils, when the antigen re-invades and binds to the high-affinity receptor of IgE on the surface of mast cells, an antigen-antibody reaction occurs, causing a change in the stability of the mast cell membrane such as the membrane structure, and an internal one. A series of biochemical changes, such as enzyme activation, promote degranulation and release of a range of chemical mediators to form a wheal.
The urticaria caused by transfusion reaction is type II allergic reaction. It is more common in patients with selective IgA deficiency. When these patients receive blood transfusion, they produce anti-IgA antibodies. After entering the blood, they form immune complexes, activate the complement system and produce anaphylactic shock. Toxins (anaphylatoxin) and various inflammatory mediators cause urticaria, red blood cell disruption and anaphylactic shock.
Type III allergic urticaria, urticarial vasculitis, is caused by immune complexes. The most common allergens are serum preparations and drugs such as furazolidone, penicillin, and less common are microbial antigens such as streptococci, tuberculosis, Hepatitis virus, etc., due to the different ratio of antigen and antibody, often the antigen is too much, so that the formed antigen-antibody complex is deposited on the blood vessel wall, activates complement, and causes mast cells and neutrophils to release inflammatory mediators such as histamine, causing blood vessels. Increased permeability and edema produce urticaria, and neutrophils release lysosomal enzymes also play an important role.
The chemical medium causing the disease is mainly histamine, followed by kinins, histamine can cause increased vascular permeability, telangiectasia, smooth muscle contraction and increased glandular secretion, causing skin, mucous membrane, digestive tract and respiratory tract. A series of symptoms, kinins, especially bradykinin also have a certain pathogenic effect, bradykinin is a peptide vasoactive substance, also has the effect of increasing vasodilation and permeability, smooth muscle contraction, about 1/3 chronic sputum Measles patients have an abnormal reaction to kininase and bradykinin, which is characterized by a delayed wheal reaction. Some chronic urticaria is associated with prostaglandin E and prostaglandin D2. Prostaglandin E has a strong and long-lasting effect. The vasodilator can cause wheal. Prostaglandin D2 is a primitive medium for mast cell activation. When prostaglandin D2 is injected, wheal and erythema and perivascular neutrophil infiltration, arachidonic acid metabolism The product may also be a medium for urticaria reaction, such as leukotrienes containing slow-reacting substances, whealing after injection, some urticaria and excessive fibrin Product or fibrinolysis resulting imbalance in, fibrin degradation products increased vasoactive effect, resulting in capillary permeability change occurs wheal.
2. Non-allergic
(1) Some substances are histamine releasing agents. After entering the body, they stimulate the mast cells to release histamine or the like, or decompose the complement C3 and C5, and produce anaphylatoxins such as C3a and C5a to release histamine and cause symptoms, such as certain drugs. Including aspirin, atropine, morphine, codeine, tetracaine, quinine, polymyxin B, hydralazine, pilocarpine, papaverine, etc. or some simple compounds such as amines, hydrazine derivatives, Tween 80 , acacia and the like can reduce cAMP in mast cells and basophils and cause histamine release.
(2) Physical, mechanical and mental factors: such as cold, compression, drinking, fever, exercise and emotional arousal can directly act on small blood vessels and act on mast cells to release histamine through changes in endogenous hormones.
(3) Toxins, snake venom, bacterial toxins, insect toxins, sea scorpion toxins, etc.
(4) Certain foods: such as aquatic shellfish, lobster, strawberry, mushroom, etc. can also activate complement to cause histamine release.
Prevention
Urticaria prevention
For urticaria, whether it is from prevention or treatment, it is the key to find out the pathogenic factors. Acute urticaria is often due to its acute onset and short course of disease. It can often find the cause and then remove the pathogenic factors. It is cured quickly, and for chronic urticaria, the cause is not ideal because the cause is unknown and cannot be prevented and treated in a targeted manner.
Identify the cause of the disease as much as possible and remove it. If you are careful to inhale pollen, animal dander, feathers, dust, castor powder, avoid contact with allergens, disable or fasten certain drugs or foods that are allergic to the body. If recurrence due to cold and heat stimulation, should not be excessively avoided, on the contrary should gradually contact, and gradually extend the time of hot and cold stimulation, in order to adapt.
Active treatment of primary diseases, such as acute tonsillitis, cholecystitis, viral hepatitis, appendicitis, intestinal tsutsugamushi, etc., to eliminate the source of the disease.
Complication
Urticaria complications Complications, diarrhea, shock, laryngeal edema
Urticaria-like vasculitis, accompanied by vomiting, diarrhea, abdominal pain and other symptoms, severe can cause shock, left heart failure, double upper limb pain and other symptoms, severe cases can cause laryngeal edema and suffocation and life-threatening.
Symptom
Urticaria Symptoms Common Symptoms Urinary histamine excretion increases skin with indentation Skin redness Itching red itch Itchy edema Lymph nodes swollen skin lined wind... Scales
According to the course of the disease, it is divided into acute and chronic. The former can be cured in a few days or weeks, while the latter is repeated for several months.
1. Acute urticaria (acute urticaria) accounts for about 1/3 of all urticaria.
(1) The onset is more urgent, and the skin lesions often occur suddenly. They are restricted to red hulls of different sizes. The boundary is clear and the shape is different. It can be round, round or irregular, and begins to isolate and gradually It can be increased and increased with the scratch, and merged into a non-plastic shape, a ground pattern or a ring shape. For example, the serum in the microvessels exudes sharply, and the wall of the tube is pressed. The wind group can be pale, surrounded by redness, and the skin is uneven and orange. Skin sample.
(2) Most of the skin lesions continue to fade for half an hour to several hours, leaving no trace after the regression, but the new wind squad appears one after another, which occurs continuously and repeatedly, and can be repeated several times in one day.
(3) Consciously itchy, burning sensation.
(4) The site is uncertain, can be generalized or limited to a certain part, sometimes the mucous membrane can also be affected, such as involving the gastrointestinal tract, causing mucosal edema, nausea, vomiting, abdominal pain, diarrhea and other symptoms, chest tightness when the throat mucosa is invaded , asthma, difficulty breathing, severe cases can cause edema of the throat and suffocation and life-threatening, such as accompanied by high fever, chills, pulse rate and other systemic symptoms, should be especially alert to the possibility of serious infections such as sepsis.
(5) Skin scratches can be positive.
(6) Blood routine examination has elevated eosinophils. If there is severe S. aureus infection, the total number of white blood cells is increased or the cell count is normal and the percentage of neutrophils is increased, or there are neutral particles at the same time.
2. Chronic urticaria (chronic urticaria) accounts for about 2/3 of urticaria. The wheal is repeated, often for a long time. It often lasts for more than 2 months, and it is light and heavy in the middle of the passage. Increased before going to bed, some have no regularity, systemic symptoms are generally mild, most patients can not find the cause.
In addition, there are some special types of urticaria in the clinic:
(1) artificial urticaria (factitious unicatia): also known as dermatographism:
1 The patient's skin is very sensitive to external mechanical stimuli. There is usually no wheal on the skin. If the skin is scratched with nails or a blunt instrument, a strip-like bulge coincides with the scratch (Fig. 1, 2), and soon disappears. Itching;
2 can be developed at any age, no obvious cause of the disease, infection in the body, diabetes, thyroid dysfunction, menopause, etc. related to the disease, can also be caused by drugs such as penicillin, also believed to be related to the existence of some abnormal function of skin mast cells;
3 The course of the disease is uncertain and can last for several months or for a long time;
4 After a very small number of skin scratches subsided 0.5h~6h, the wheal reaction appeared in situ and lasted for 48h. This is called delayed dermatographism.
(2) Peptone urticaria (acute protein allergic urticaria): caused by peptone decomposed by food protein. Under normal circumstances, peptone is easily digested and not absorbed into the blood, but it is overeating and energetic or At the same time drinking, peptone can be absorbed into the blood through the intestinal mucosa and cause disease, skin congestion and redness, wheal, headache, fatigue, the general course of disease is short, can be resolved in 1 ~ 4h, sometimes lasting hours or 1 to 2 days, Is an antigen-antibody reaction.
(3) cold urticaria (cold urticaria): both acquired and familial.
1 Familial cold urticaria: is an autosomal dominant inheritance, rare, begins to develop soon after birth, sustainable life, pathogenesis and media are unclear, more common in women, symptoms can be reduced with age, general exposure After 0.5 to 4 hours in cold or cold water, it is a red rash that does not exceed 2cm in diameter. It is a non-genuine wheal. It does not itch and has a burning sensation. It is often accompanied by chills, fever, headache and joint pain and increased white blood cells. Symptoms, the ice test is positive, that is, ice cubes are placed on the skin of the forearm of the patient. After 2 minutes, a typical wheal can be induced at the site, and the passive transfer test is negative.
2 acquired cold urticaria: may be autoimmune allergic reactions, allergic to cold, most of them are idiopathic, about 1/3 have a history of genetic allergy, often starting from children, in sudden temperature drop, exposure to cold wind, cold water After cold or cold, wheal or plaque edema may occur at the exposed or contact site, which may last for 0.5h~4h. In severe cases, there may be hand numbness, lip numbness, chest tightness, palpitations, abdominal pain, diarrhea, syncope and even shock. When it occurs, it can cause cold shock or even drowning. It is estimated that about 25% of patients can cause swelling of the mouth and throat when they enter the cold diet. In severe cases, suffocation and death occur. The antibody is IgE. It is believed that cold can make certain normal metabolites in the body. It becomes an antigen, which causes the production of antibodies. It may also change the stereostructure of the skin protein due to cold factors and become an antigenic substance that the antibody cannot recognize its own tissue protein. The formation of the wheal is due to the IgM macromolecular globulin after the skin is cold. As a result of accumulation, the main mediators are histamine and kinin, and the pathogenesis is IgE-mediated immediate allergic reaction. The ice test is positive, and it can also be tested by ice water dipping. The arm can be immersed in 5~10 °C cold water for 5 min. If the wheal and erythema are positive, the passive transfer test is positive. In rare cases, cold urticaria can occur in globulinemia (myeloma, giant ball). Proteinemia, leukemia, liver disease, systemic lupus erythematosus, paroxysmal cold hemoglobinuria (syphilis), cold fibrinogenemia, cold solubilemia, especially in patients with mononucleosis.
(4) cholinergic urticaria: also known as small papular urticaria or systemic heat urticaria, more common in young people aged 23 to 28, due to exercise, heat, emotional stress, eating hot drinks or alcoholic beverages, etc. Inducing factors such as temperature rise stimulate the central nervous system, stimulate the sweat gland nerve junction through cholinergic afferent nerve, cause acetylcholine release, occur in mast cells, or occur due to insufficient cholinesterase, accounting for 5% of urticaria ~7%, the skin lesions are characterized by a small wind group of 1 ~ 3mm in diameter, surrounded by redness, evacuation distribution, non-integration, more than 2 to 10min after the above factors stimulate rash, lasting 30 ~ 50min, rarely more than 3h, rash That is, all disappeared, palmar sputum rarely occurs, consciously itchy, sometimes there is a refractory period of 8 to 24 hours after each onset, during this time, even if the above stimulation is encountered, there will be no rash, about near One third of patients may be accompanied by headache, perioral edema, tearing, eye pain, runny nose, nausea, vomiting, abdominal pain and other symptoms. A few have dizziness, hypotension, asthma attacks, etc., and the course of disease gradually improves after several years. At 1:5000 vinegar Scratch test or skin test positive (the methacholine) as may occur at the injection site wheal, and the advent of satellite-like small wind group (normal rare) around, but repeating the same patient or patients with mild test results are often inconsistent.
(5) Solar urticaria: After exposure to sunlight or artificial light source for several seconds to several minutes, local itching, erythema, wheal, occasional angioedema, severe rash may be chilly, fatigue, Syncope, spastic abdominal pain, bronchospasm, etc., often idiopathic, sometimes associated with systemic lupus erythematosus, erythropoietic protoporphyrin, etc., according to its possible pathogenesis and light response to different wavelengths It can be divided into 2 major categories and 6 subtypes. The first major category is generally considered to be related to IgE allergic reaction, but no related pathogenic antigen has been found yet. This type is divided into 3 subtypes, namely type I and type IV. And type VI, type I is mainly allergic to short-wave ultraviolet rays of 280-320 nm. After irradiation, localized skin can be seen to release histamine, mast cells degranulate and appear neutral, eosinophil chemotactic factor, type IV is 400-500 nm. Visible light allergy, it is now confirmed that this type is an inherited metabolic disease, may be a skin manifestation of delayed cutaneous porphyria, the photosensitive source is protoporphyrin IX, but different from other porphyria, The urinary porphyrin excretion is normal, while the erythrocyte protoporphyrin, fecal porphyrin and coproporphyrin are increased. Such patients can activate the complement system in the serum after illuminating, and produce a series of inflammatory reactions. The type VI is caused by light of 400-500 nm. The difference from type IV is caused by -carotene, and the other category includes three subtypes. Type II is caused by 300-400 nm long-wavelength ultraviolet light, type III is visible light of 400-500 nm, and type V is 280-500 nm. The broad-spectrum light is generally considered to be unrelated to the immune response, and most of them cannot be found, but a small number of patients belong to the early or late stage of SLE, and may also be caused by drugs such as ibuprofen, sulfonamide, and chlorpromazine.
(6) Compressive urticaria: 4 to 8 hours after skin compression, local edema of red edema, often deep edema, involving the dermis and subcutaneous tissue, similar to angioedema, burning or pain, It lasts for about 8~12h, and about half of the patients may have fever, sweating, dizziness, headache, nausea, fatigue, weakness, shortness of breath, irritability and other systemic symptoms. There are still a few mental depressions, which are common in the bottom of the foot after walking. In the oppressed areas such as the buttocks, the white blood cell count can be slightly increased, and the pathogenesis may be related to kinins. Some 94% of these patients are accompanied by chronic urticaria, and 43% are positive for the aspirin challenge test, 63 % with scratches, but not related to genetic allergy, most stress urticaria is delayed, but very few are immediate, skin lesions appear 20 minutes after local compression, a clear diagnosis can be done as follows: hanging with broadband Hang the 2~10kg weight under the shoulder, or let the patient take the seat, suspend the broadband in the middle of the thigh for 10~30min, observe the broadband immediately, and observe it continuously at 4,6,8h, until 20h, and At the same time, scratches on the back to confirm the presence of scratches. If the scratches are positive, the test can be repeated for 2 hours.
(7) Serum pathological urticaria: due to the application of allogeneic serum, including various anti-venom serum, vaccine, gamma globulin or albumin, blood transfusion and other serum and its products provided by humans or animals, caused by blood, during injection Areas or whole body erythema, itching and wheal, etc., there are also ring erythema, nodular erythema, etc. In addition, about 2.7% of patients may also have fever, lymphadenopathy, myalgia, joint pain, cyanosis, low Systemic symptoms such as complementemia, called serum disease, have self-limiting symptoms and gradually disappear, but there are also a few severe cases that can cause death, about 1% to 3% of recipients, after the blood transfusion occurs throughout the body Urticaria is currently thought to be caused by the formation of immune complexes, causing changes in blood vessels and smooth muscles. It can also indirectly lead to the release of mediators from mast cells by anaphylatoxins. It is found that 15% to 20% of recipients have anti-IgA in the blood. The IgG antibody can form an immune complex with IgA in the blood of the donor, and activates complement to cause urticaria and angioedema, but some antibodies are not found, such as ramie can also occur after the input of gamma globulin. Because due to the input gamma globulin, immunoglobulin G concentration in the blood increased, mutual cohesion, due to fix complement.
(8) Contact urticaria: Wind lumps occur after skin contact with certain allergens. Erythema can be divided into three types: immune, non-immune and unclear. Non-immune contact urticaria is caused by primary Caused by urticaria, no sensitization, almost all contacts can occur, the pathogenesis is that the contact substance directly stimulates mast cells to release histamine, slow-reacting substances, bradykinin, etc., and the more common substances are animals or plants. Such as jellyfish, ramie, caterpillars, pink butterflies, etc., a variety of chemicals can also be caused, according to the survey, about 88% of adults have a positive reaction to 5% benzoic acid, 85% of people are positive for 5% benzoic acid 58% of the people were positive for 25% sorbic acid. Most of them reacted after 45 minutes of exposure to the above substances and resolved within 2 hours. These substances may be caused by non-immune reactions, but also by immune reaction. Limited to the contact site, it can also be generalized. To determine the contact substance, the most common method is to do the patch test. Most cases of immune contact urticaria are IgE-mediated immediate allergic reactions. Substances are fish, shrimp, vegetables, animal hair, dander, eggs, and other drugs and chemical substances, which differs from that of the non-immunity:
1 Generally, the first contact will not produce a wheal, and it will take several times to get sick;
2 people with allergies, such as asthma, hay fever (hay fever), eczema patients, are more likely to occur;
3 Once the disease occurs, in addition to itching, red, and wind stagnation at the contact site, rhinitis, conjunctivitis, asthma, diarrhea, abdominal pain, nausea, vomiting and other systemic symptoms may occur;
4 In addition to contact parts such as hands, inhalation and mouth contact may also cause a reaction;
5 Responders are mostly proteins, drugs or chemicals. Itching, burning, erythema, wheal and even blisters may occur within a few minutes to 1-2 hours after exposure. It may still cause drooling, tearing, wheezing, abdominal pain, diarrhea. , vomiting and even suffocation, shock and other systemic reactions, also known as allergic contact urticaria syndrome, an unidentified person with a combination of immune and non-immune manifestations, such as ammonium sulfate.
(9) water-borne urticaria and water-borne pruritus: contact with any temperature of water can cause itching, a small number of urticaria can occur, the wind group is small, tap water wet compress the back, typical lesions appear within 30min, there are reports in the family There are similar patients, only itching and no urticaria are often idiopathic, also seen in the elderly dry skin, also seen in polycythemia, Hodgkin's disease, myelodysplastic syndrome, eosinophilia In patients with syndromes, watery itching can also occur in patients with acute episodes of hematological disease. Experiments have shown that patients with idiopathic watery pruritus and urticaria have elevated levels of histamine in the blood, and there are mast cells in the lesion tissue. Particles, passive transfer test negative, oral H1 receptor antagonist 1 h before bath can reduce wind formation.
(10) Autoimmune urticaria: It is named after circulating autoantibodies in the serum of some patients with chronic idiopathic urticaria. According to statistics, autoantibodies are found in at least 30% of patients with chronic idiopathic urticaria. Intravenous injection of autologous serum can produce wheal and erythema reaction, anti-IgE or anti-high affinity IgE receptor (FcRla) IgG-type autoantibodies, both of which release histamine, can stimulate blood eosinophils Cells, urticaria is directly related to the amount of autoantibody FcRIa in serum.
(11) Adrenal urticaria: a small, itchy wheal, surrounded by white halo, when emotionally excited, ingestion of coffee can cause, intradermal injection of norepinephrine can occur in the wind group, the disease is due to sympathy The norepinephrine secretion secreted by the nerve endings should be differentiated from cholinergic urticaria. The clinical treatment often uses -blockers and antihistamines to avoid epinephrine.
(12) Urticaria vasculitis: characterized by urticaria and necrotizing vasculitis, reported by Mcduffie in 1973, histology showing leukocyte fragmentation vasculitis, due to persistent and severe hypocomplementemia in some cases Therefore, it was named as low-complement vasculitis. Many scholars have successively diagnosed necrotizing venous urticaria and low-complement vasculitis urticaria syndrome. It is considered that urticaria vasculitis is more suitable. The patient had recurrent chronic urticaria damage, often lasting for more than 24 hours, a few had laryngeal edema, accompanied by irregular fever, arthritis, joint pain, swollen lymph nodes, abdominal pain, accelerated erythrocyte sedimentation rate, individual kidney damage, 32% of patients Low complement syndrome occurs, after the skin lesions subsided, leaving purpura, scaly and pigmentation, consciously mild itching and pain, and found that there is immune complex deposition (type II allergic reaction) in the venules of the capillaries, which may be the cause.
The disease can be divided into two subtypes of hypocomplementemia and normal complementemia. The systemic damage of the former is greater than the latter. Prednisone, indomethacin (indomethacin), colchicine , Dapsone and other treatments are effective.
(13) angioedema: angioedema (angioedema), also known as angioedema (edioneurotic edema), unkle edema (Quincke edema) or huge urticaria (urticaria gigantra), is a subcutaneous tissue loose site or The localized edema of the mucosa is divided into acquired and hereditary. The latter is rare. Acquired angioedema is often accompanied by other allergic diseases. Its etiology and pathogenesis are similar to those of urticaria. Acute The authors may be caused by IgE-mediated type I allergies, contrast agents and some drugs such as non-steroidal anti-inflammatory drugs (aspirin, indomethacin), codeine and angiotensin converting enzyme inhibitors, etc. Immune mechanism causes foods such as fruits and fish. The inhalation is mainly feathers and animal dander. The authors of delayed infection are often caused by cold and sunlight. In addition to hereditary angioedema, angioedema is often accompanied by urticaria. About 15% to 20% of people have urticaria, angioedema or both, but the incidence of chronic urticaria or angioedema is low, and angioedema often occurs in 30~ At the age of 40, women have the highest incidence at 40 to 50 years old, and about 50% of patients develop symptoms after 5 years of age. After 20 years of age, 10% to 20% of patients have intermittent occurrence.
1 hereditary angioedema (hereditary angioedema HAE): hereditary angioedema is an autosomal dominant genetic disease, first reported by Robest Grave in 1843, then in 1882 Quincke reported that two cases occurred in the same family, after Scholars gradually recognized their hereditary nature, which was named hereditary angioedema. The pathogenesis was closely related to the system of complement, coagulation, fibrinolysis, kinin formation, etc. The patient had biochemical abnormalities and it was observed that intradermal injection of vasopressin was given to patients. (Kallikrein, a proteolytic enzyme) usually does not respond and demonstrates the lack of CIINH protein in serum. This inhibitor is also anti-vasopressin. It is thought that 85% of patients are due to CI cholinesterase inhibitor in blood (CIEI). The level of the disease is reduced. In addition to the decrease in CIEI, 15% of patients have dysfunction, resulting in excessive activation of CI, which in turn activates C4 and C2 to release kinins. With the involvement of plasmin, kinins increase vascular permeability. And cause mast cells to release histamine, angioedema, C4 and C2 decreased at the onset, C4 decreased in the quiescent period, most cases occurred in late childhood or adolescents, most Family history, often involving several generations, but about 20% have no positive family history, clinical features characterized by recurrent, localized, non-invasive subcutaneous edema, no erythema and itching, due to the expansion of skin and subcutaneous tissue Feeling pain, the onset of the disease is spontaneous, about half of the patients are related to minor trauma, such as collision, squeezing, lifting heavy objects, sex life, horse riding, etc., generally 4 to 12 hours after trauma, swelling, some patients with onset Emotional, infection, sudden changes in temperature, and frequent estrogen-type contraceptives before and after menstruation, during the onset, edema progressively worsened within a few hours, subsided to normal within 24 to 72h, to limbs (96%) , facial (85%), intestinal mucosa (88%) and oropharynx involvement are more common, lesions up to several centimeters in diameter or occupying a limb, swelling of the face and lips can be carried out and involving the upper respiratory tract, all patients with skin damage Have different degrees of gastrointestinal symptoms, recurrent abdominal pain can be the only manifestation of this disease in most family members, abdominal cramps like acute abdomen can occur, acute laryngeal edema is the most serious and endangered Life performance, 26% of untreated patients may die because of laryngeal edema.
2 acquired angioedema (acquired angioedema): the skin lesions are acute limited swelling, involving the subcutaneous tissue, the border is unclear, showing normal skin color or reddish, the surface is bright, the touch is elastic, often occurs in the eyelids, lips, The earlobe, vulva (the most common part of the foreskin) and other loose parts of the tissue, or the mouth, tongue, if it occurs in the mucous membrane of the throat can cause difficulty in breathing, and even suffocation leads to death, often accompanied by urticaria, damage often single, It lasts for 2 to 3 days and often recurs. It often occurs repeatedly in the same part. This disease often occurs at night. When you wake up, you will find that there is often no itching, even if it is mild, or only mild burning and discomfort. A quarter of cases have a history of recurrent erythema. The erythema may appear before edema, or it may occur at the same time, or it may not be related to the onset of edema. The disease may involve the visceral mucosa. When it affects the gastrointestinal tract, abdominal cramps may occur. , nausea, vomiting, can not ventilate and other acute intestinal obstruction performance, severe dehydration and blood pressure drop, barium meal angiography can show mucosal edema.
Examine
Urticaria examination
According to the repeated appearance of the skin, the rapid wheal, itching, leaving no traces, and the characteristics of various types of urticaria are easy to diagnose, but should be identified in the following diseases, if necessary, laboratory tests (including chest X-ray) Check abdominal B ultrasound, etc.) and related tests (such as exercise, hot water, sunlight, ice), allergen testing, etc. to further clarify the cause.
The following laboratory tests can be performed if the clinical symptoms are difficult to diagnose or if the cause is further sought.
1. Suspected rheumatism caused by urticaria can check erythrocyte sedimentation rate, anti-nuclear antibodies, etc., serum complement determination, skin biopsy is helpful for the diagnosis of urticaria caused by complement activation.
2. For cold urticaria, syphilis serum test should be carried out to test cold globulin, cold fibrinogen, cold hemolysin and ice test, anti-nuclear antibody and other tests.
3. Solar urticaria should be checked for feces, urinary porphyrins, etc., should be distinguished from SLE.
4. Suspected to be related to infection, or a history of hepatitis in the liver or medical history at the time of physical examination, feasible blood routine, hepatitis B antigen, antibody test, stool eggs, fungi, X-ray examination of the lesion.
5. If thyroid disease is suspected, anti-microsomal thyroid antibody-related tests should be performed.
6. If you suspect that you are allergic to inhalation or ingestion, you should take an allergen test. If it is positive, you can take desensitization treatment.
7. Patients with serum urticaria have fever and joint pain. ESR should be examined. For example, erythrocyte sedimentation rate has important diagnostic value.
8. In addition to the obvious low-complementemia in the onset of urticaria vasculitis, the subunit Cla of serum Cl is significantly reduced, C4, C2 and Cg are moderately to severely reduced, and circulating immune complexes and low molecular weight Clq precipitates appear in serum. Direct immunofluorescence showed immunoglobulin and complement deposition in the skin wall of the skin.
9. Autoimmune chronic urticaria can detect autoantibodies, using its own serum skin test: routine blood draw in a sterile tube for 30min, centrifugation, take serum 100l to the patient for intradermal test, with normal saline as a control, such as 1h After the local appearance of the wind group diameter greater than 9mm is positive, other such as histamine release test, immunoblotting and enzyme-linked immunosorbent assay can be used.
Angioedema, especially hereditary angioedema, should be used for serum complement examination. It should be determined as the fourth component of complement (C4). If C4 is low, there may be a lack of complement first component esterase inhibitor (ClINH). Stage C4 is significantly lower than normal, and is lower than normal in the remission period. Even if there is no family history, the disease can be diagnosed. Conversely, if C4 is normal, the disease can be denied.
Chronic urticaria histopathology: simple local edema, serous exudation of the upper nipple and dermis, papilledema, a small amount of lymphocyte infiltration around the blood vessels, but infiltration can also be dense and mixed with eosinophils.
Diagnosis
Urticaria diagnosis and identification
diagnosis
Urticaria is a wheal of skin lesions, which suddenly occurs, quickly resolves, and leaves no traces after disappearing. According to the characteristics of each type, it is not difficult to diagnose. It is difficult to find the cause. It is necessary to ask the medical history in detail and make a careful and detailed physical examination. It is very important to comprehensively analyze the disease and to find out the relevant factors of the disease in combination with various characteristics.
Angioedema can be resolved within a few hours to 2 to 3 days depending on the sudden occurrence of a large piece of temporary non-recessed swelling, often involving the eyelids, lips, tongue, external genitals, hands, feet, etc., the diagnosis of this disease is not difficult.
The diagnosis of hereditary angioedema can be based on medical history, positive family genetic history and serological examination. When the following clinical manifestations are available, the possibility of this disease should be suspected:
1. Repeated episodes of localized edema.
2. There is self-limiting, generally 1 to 3 days can be relieved by itself.
3. Repeated episodes of laryngeal edema or unexplained abdominal pain.
4. With emotions, menstruation, especially trauma and other incentives.
5. Itching is not accompanied by urticaria.
6. Treatment with antihistamines and adrenocortical hormones is not effective.
7. There is a positive family history, and nearly half of the members of the family have a disease.
8. Serum lipase inhibitory protein C4 and C3 values are reduced.
Differential diagnosis
Urticaria needs to be differentiated from papular urticaria and polymorphic erythema. Patients with abdominal pain and diarrhea should be distinguished from acute abdomen and gastroenteritis. Those with symptoms of high fever and poisoning should be considered as symptoms of severe infection. First, angioedema must be differentiated from substantial edema such as erysipelas, cellulitis and orbital contact dermatitis, adult scleredema, facial swollen malignant reticulosis, acquired angioedema and hereditary blood vessels. Sexual edema can be identified according to the above points.
First, the identification of infant eczema
Infant eczema refers to skin damage caused by eczema in infancy. Infant eczema can include atopic dermatitis in infants, but atopic dermatitis cannot equal or replace infant eczema, infant eczema includes infant contact dermatitis; seborrheic and rubbing Rotten infant eczema; atopic dermatitis in infants.
Second, the identification of angioedema
Angioedema is chronic, recurrent, large areas of local edema in the deep and subcutaneous tissues of the dermis. The etiology and pathogenesis are the same as those of urticaria, except that the plasma exudes from the interstitial space of small blood vessels in the deep or subcutaneous tissues of the dermis. Caused by loose tissue around.
Third, identification with gastroenteritis and some acute abdomen
Urticaria-like vasculitis wheal lasts for 24 to 72 hours, accompanied by fever, joint pain, increased erythrocyte sedimentation rate, hypocomplementemia, pathological examination for broken vasculitis, accompanied by vomiting, diarrhea, abdominal pain and other symptoms It should be differentiated from gastroenteritis and certain acute abdomen.
