Allergic reactions (what are the common allergic reactions?)
Allergic diseases refer to the hypersensitivity of the immune defense system in the body when the human body comes into contact with allergens (also known as allergens). A class of diseases that cause tissue and organ damage or physiological dysfunction.
Normal people have a protective immune defense system. When foreign harmful substances invade the human body, the human body can clear these harmful substances through the protective immune defense system. The sensitivity of the immune defense system of allergic people is much higher than that of normal people. Some foreign substances that are harmless to the human body, such as pollen, protein, etc., are often considered as invaders, and they try to get rid of them .
At this time, some normal tissues and organs in the body will be damaged, and there will be respiratory mucosal edema, congestion, smooth muscle spasm, nasal congestion, and a large amount of nasal mucosa secretion Various allergic reactions such as thin liquid, itchy skin or erythema.
Clinical common allergic diseases include four categories: anaphylactic shock (systemic anaphylaxis), respiratory tract allergic reaction, digestive tract allergic reaction, skin allergic reaction. Anaphylactic shock includes drug anaphylactic shock and serum anaphylactic shock.
Drug anaphylactic shock is the most common type of penicillin anaphylactic shock. This is because penicillin has a small molecular weight and is generally not immunogenic. However, when penicillin thiazole aldehyde or penicillin acid is degraded, it combines with tissue protein to obtain immunogenicity, which can stimulate the body to produce specific IgE antibodies and sensitize the body. Anaphylactic shock may occur when penicillin is re-exposed.
Of course, clinically, one of the few people exposed to penicillin may also have anaphylactic shock, which may be related to the patient’s unintentional exposure to penicillin or penicillin-like substances. Such as the use of syringes or other penicillin-contaminated instruments, inhalation of penicillin degradation products or penicillin spores from the air.
Serum anaphylactic shock is common in animal immune sera such as tetanus antitoxin, diphtheria antitoxin, snake venom antitoxin, etc. Some patients may develop anaphylactic shock due to injection of the same animal serum preparation, that is, symptoms similar to drug anaphylactic shock, and severe cases may die within a short time.
Inhalation of antigenic substances such as plant pollen, animal fur, and dust mites can cause respiratory allergic reactions. The main manifestations are bronchial asthma and allergic rhinitis. There are two types of bronchial asthma: early response and late response. The former attack quickly and disappear quickly. Histamine and other biological activities mediate early asthma. The latter occurs slowly and lasts for a long time. At the same time, some cells such as eosinophils (a type of white blood cell) and Th2 cells infiltrate, and the inflammatory response is mainly caused by white blood cells and PAF (platelet activating factor) released by the cells.
Alimentary tract allergic reactions are mainly seen in allergic reactions caused by eating fish, shells, eggs, milk and other foods by mistake or taking certain drugs. for nausea, vomiting, diarrhea,Abdominal pain and other symptoms. Studies have found that the content of secretory IgA in the gastrointestinal tract of people prone to food allergy is significantly reduced, and most of them are accompanied by proteolytic enzyme deficiency. Therefore, the defense function of the intestinal mucosa of patients is weakened, and the intestinal wall is easily damaged, so that some food proteins in the intestinal tract can be absorbed through the mucosa before they are completely decomposed, thereby inducing allergic reactions in the digestive tract as allergens.
The last category is allergic skin reactions. The main manifestations are skin urticaria, eczema and angioedema. It can be caused by allergens such as drugs, food, feathers, pollen, and intestinal parasites.
Once an allergic reaction occurs, the patient should seek medical attention in time to determine the allergen as soon as possible for further treatment. Don’t make your condition worse because of your random guesses, otherwise the gain outweighs the loss.