Urticaria is commonly referred to as a rubella block. It is a localised oedema reaction that occurs due to the expansion of the skin, mucous membranes, and permeability. It usually resolves within 2 to 24 hours, but new skin rashes are repeated. The course of the disease lasted several days to several months. More common in clinical practice.
Common Causes of Urticaria
sunlight and other stimuli, mental and genetic factors, etc.
- Often itchy skin
- Redness or skin wheal
The cause of urticaria is very complicated, and about 3/4 of patients cannot find a cause, especially chronic urticaria.
Common causes are food and food additives; inhalants; infections; drugs; physical factors such as mechanical irritation, cold and heat, sunlight, etc. insect bites; mental factors and endocrine changes; genetic factors.
Types of urticaria
Skin scratch urticaria
The patient’s weaker mechanical stimuli cause increased physiologic reactions and produce wheal on the skin. After the scratching, or in tight belts, garters, etc., the patient whetted locally and itched.
Delayed skin scratches
Skin scratches appear wheal and erythema 6 to 8 hours after stimulation and wheal groups last 24 to 48 hours. There are more than one late lesions, which form small segments or points along the scratches.
The damage is broader or broader, and it even expands into blocks on both sides. Local fever, tenderness.
Delayed stressful urticaria
The rash occurs 4 to 6 hours after topical skin compression, usually for 8 to 12 hours. It manifested as local, deep, painful swelling, accompanied by chills, fever, headache, joint pain, general malaise, and mild white blood cell counts. A local swelling of large areas like vasogenic oedema, prone to occur before the occurrence of palmoplantar and hip lesions can have a 24-hour incubation period.
The rash is characterised by the occurrence of a small whirlpool of 1-3 mm in general, except for the palm iliac crest, and there are obvious circles around it. The satellite-like wheal sometimes can be seen, and the thin, sparse wheal that is flush or barely flush can be seen.
Sometimes the only symptom is itching and no wheal. Damage lasts 30 to 90 minutes, or up to several hours. Mostly occur during exercise or shortly after exercise, accompanied by itching, tingling, burning, heat or skin irritation. It can also be induced by heat or emotional stress.
Can be divided into family and acquired two. The former is rare and is an autosomal dominant inheritance. The delayed reaction occurs within half an hour to four hours after cooling. The rash is a wheel that does not itch and may have a bluish purple centre.
The skin rash lasts 24 to 48 hours. There is a burning sensation, accompanied by fever, Joint pain, increased white blood cell counts and other systemic symptoms. The latter is more common.
Patients often experience a sudden drop in temperature or after contact with cold water. Itching and wind bleeds occur locally within minutes and are more common in the face and hands. Other sites in severe cases may also be involved. Headaches, skin flushing, low blood pressure, and even fainting may occur.
After the skin is exposed to sunlight for a few minutes, itching, erythema, and wheal are rapidly occurring locally. The wheal subsided after about 1 to several hours. The rash can be accompanied by chills, fatigue, syncope, and intestinal spasms that disappear within hours.
It is characterised by the formation of wheal and erythema in the skin in contact with specific allergens. Can be divided into immune mechanisms and non-immune mechanisms 2 categories. Non-immune is caused by the direct action of primary stimulants on mast cells to release histamine and other substances. Almost all of the contacts are onset without substance sensitisation. The immunity is typed me allergy and specific IgE antibodies can be detected.
Diagnosis of Urticaria
The disease can be diagnosed according to a clinical wheal-like rash. The diagnosis is generally not difficult, but the cause of urticaria is complicated. It is often difficult to determine the cause of urticaria. Therefore, it is necessary to take a detailed medical history, detailed physical examination, and related laboratory tests to make urticaria as clear as possible.
Treatment of Urticaria
- General treatment
Because of the various causes of urticaria, the treatment effect is not the same. The specific treatment measures are as follows:
(1) Removal of Causes Every patient should seek to find the cause of the attack and avoid it. If infection causes it, active infection should be treated. Allergic drugs should be stopped when the drug causer causes food allergies. After identifying allergic foods, do not eat the food.
(2) To avoid predisposing factors such as cold urticaria should pay attention to keep warm, acetylcholine alkaline urticaria to reduce exercise, sweating and mood swings, contact urticaria to reduce the chance of exposure and so on.
- Drug treatment
(1) Antihistamines 1H receptor antagonists have a strong anti-histamine and anti-inflammatory mediators and have a good effect on all types of urticaria. Commonly used H1 receptor antagonists are diphenhydramine, cyproheptadine, chlorpheniramine, etc.
Avastin, cetirizine, imidazoline, loratadine, ebastine, Azelastine, Desloratadine, etc.; when treatment alone is ineffective, two different types of H1 receptor antagonists may be used in combination or in combination with H2 receptor antagonists. The commonly used H2 receptor antagonists are cimetidine and thunder. Nitinidine, famotidine, etc. Used for acute, chronic urticaria and cold urticaria. The dose varies from person to person.
(2) Inhibition of degranulation of mast cells and reduction of histamine release drugs
1 metaxy-isobutylene sulfate is a β2 adrenal receptor promoter that increases the concentration of camp in the body, thereby inhibiting the degranulation of mast cells.
Ketoticophenol inhibits the degranulation of mast cells by increasing the concentration of cAMP in the body and prevents the release of inflammatory mediators (such as histamine, slow-reacting substances, etc.).
It’s suppression. The production is stronger and faster than cromolyn sodium and can be taken orally.
3 Cromolyn sodium can block the binding of antigens and antibodies and inhibit the release of inflammatory mediators. If combined with glucocorticoids, the amount of the latter can be reduced, and enhance the efficacy.
4 Tranilast reduces histamine release by stabilizing the mast cell membrane.
Second-line medications for the treatment of urticaria, which are generally used for severe acute urticaria, urticarial vasculitis, stress urticaria ineffective against histamine, or chronic urticaria severe insult, intravenous drip or oral, should avoid long-term application.
Commonly used drugs are as follows: 1 prednisone; 2 Qu Anxi Long; 3 dexamethasones; 4 Debao Song. In emergencies, intravenous infusions of hydrocortisone, dexamethasone, or methylprednisolone are used.
When chronic urticaria patients have an autoimmune basis and the condition is repeated, and the above treatment fails to achieve a satisfactory therapeutic effect, an immunosuppressive agent can be used. Cyclosporine has a good effect, and azathioprine, cyclophosphamide, methotrexate, and immunization are available.
Globulin can be tried, Tripterygium also has a certain effect. Due to the high incidence of side effects of immunosuppressive agents, treatment of urticaria is generally not recommended.
In addition, drugs that reduce vascular permeability, such as vitamin C, vitamin P, and calcium, are often combined with antihistamines. Those who are caused by an infection may choose appropriate antibiotics.