contact urticaria
Introduction
Introduction to contact urticaria Contact urticaria refers to the occurrence of wheal and erythema after skin contact with certain allergens. It can be divided into three types: immune, non-immune and unclear. Non-immune contact urticaria is more common. basic knowledge The proportion of illness: 0.03% Susceptible people: no special people Mode of infection: non-infectious Complications: Asthma, anaphylactic shock
Cause
Contact urticaria cause
The causes of contact urticaria can be divided into non-immune, immune and unexplained causes.
1. Non-immunological contact urticaria does not require sensitization and can cause all contacts to develop symptoms. Such as dimethyl sulfoxide, cobalt oxide solution, benzocaine, certain preservatives, seasonings, insect toxins and the like.
2. Immunological contact urticaria is a type I allergy with antigen-specific IgE. May be associated with angioedema, asthma, rhinitis, conjunctivitis, gastrointestinal or mouth and throat disorders. The source of the disease may be certain foods, textiles, animal dander, cosmetics, industrial chemicals, drugs, and the like.
3. Unexplained contact urticaria has both immunological and non-immune manifestations, such as those caused by ammonium sulphate.
Prevention
Contact urticaria prevention
Contact urticaria refers to the occurrence of wheal and erythema after skin exposure to certain allergens. It is easy to cause recurrence after being affected by external factors. Patients should learn to prevent contact urticaria and pay attention to it in daily life. .
1, eat less fish and shrimp seafood, canned artificial flavors, preservatives, yeast and other artificial additives, salted foods, eat less irritating food.
2, to maintain indoor and outdoor cleanliness, the home should be less pets such as cats and dogs. Avoid inhaling pollen, dust, etc.
3, allergic patients should be as little as possible to contact rubber gloves, hair dyes, flavored soap and detergent, chemical fiber and wool clothing.
4, people suffering from cold urticaria do not go to the beach, can not wash cold water bath, winter should pay attention to keep warm. Cholinergic urticaria should keep your body cool and avoid sweating.
5, to avoid drugs that can cause contact urticaria, such as penicillin, tetracycline, chloramphenicol, streptomycin, sulfonamides, polymyxin and other antibiotics, analgin, aspirin and other antipyretic analgesics, cold clear Chinese medicine such as Niuhuang Jiedu Tablet.
6, active treatment of parasitic infections, bacterial infections, viral infections, fungal infections, diabetes, hyperthyroidism, menstrual disorders and other diseases.
7. The onset and exacerbation of contact urticaria have a certain relationship with people's emotional or psychological stress. They should maintain a healthy mentality and improve their body resistance.
Complication
Contact urticaria complications Complications asthma anaphylactic shock
Allergic contact urticaria syndrome.
Symptom
Symptoms of contact urticaria Common symptoms Skin itching erythema-like rash Wind group local burning tears abdominal pain asthma diarrhea nausea and vomiting
Non-immunological contact urticaria: After skin contact with the diseased material, it may cause local urticaria such as itching, erythema and wheal in 15~30 minutes. Often the endothelial rash subsides in a few hours. The rash can be limited to the contact area, and can also be spread throughout the body. May be associated with angioedema and allergic reaction syndrome.
Immune contact urticaria: There are generally no systemic symptoms, mainly symptoms caused by various allergens, such as asthma, rhinitis, gastrointestinal tract and throat and throat dysfunction.
The difference between immunological contact urticaria and non-immunity is:
1. Generally, the first contact will not produce a wheal, and it will take several times to get sick;
2, those 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, systemic symptoms such as rhinitis, conjunctivitis, asthma, diarrhea, abdominal pain, nausea, and vomiting may occur.
4. In addition to contact parts such as hands, inhalation and mouth contact may also cause a reaction;
5. Most of the responders are proteins, drugs or chemicals. In addition to itching, burning, erythema, wheal, and even blister within minutes to 1 to 2 hours after exposure, systemic reactions such as salivation, tearing, wheezing, abdominal pain, diarrhea, vomiting, and even suffocation, shock, etc. may also occur. Sexual urticaria syndrome.
Examine
Contact urticaria examination
Sensitizers can be used for patch test. Closed patch test, which is usually used to check delayed type allergens, is often not applicable, and often has a false negative reaction to pathogenic substances. This is because most contact urticaria causes rapid and sensitive reactions, but after the disease-causing substance continues to stimulate for a period of time, the skin no longer responds, and the formation of new rashes cannot be maintained for a long time. Contact urticaria is an immediate skin reaction that must be observed and determined within 30 to 60 minutes after the skin test.
Diagnosis
Diagnosis and identification of contact urticaria
First of all, you should ask about the history of exposure and changes in the condition. From the contact of the patient's occupation or living environment, you can find clues about the pathogen.
Use a patch of sensitizing substance to apply to normal skin. After 15 to 30 minutes, the wheal can be determined.
