(Expert: Lin Xiaoqing, a dermatologist at the Minnan Branch of the First Affiliated Hospital of Fujian Medical University, the original first release of China Popular Science Micro Platform)
Urticaria is a "frustrating little goblin" because once it attacks, it spreads all over the body and itches extremely unbearably. Moreover, it is difficult to find the cause of urticaria. When I go to the doctor, the reply I get is always that the resistance is too low. So today, let’s follow a dermatologist to find out what causes urticaria? What are the causes? What should you do if you suffer from urticaria?
Picture source network
What are the factors that cause urticaria?
Urticaria, commonly known as "urticaria", is an allergic disease. It is a localized edema reaction caused by the dilation and increased permeability of small blood vessels in the skin and mucous membranes. It usually subsides within 2 to 24 hours, but The recurrence of new rashes, lasting for days or months, is a relatively common disease in dermatology clinics. 15% to 20% of people have at least one episode of urticaria in their lives.
What's more troublesome is that the causes of urticaria are complicated, and about 3/4 of the patients cannot find the cause, especially chronic urticaria. So, what are the common factors that can cause urticaria?
1, drugs. Urticaria is often caused by drugs, such as penicillin , furosemide, and sulfa drugs.
2, food. Fish, shrimp, crab, eggs, milk, etc. containing special proteins are common pathogenic factors; certain plant foods, such as eggplant, bamboo shoots, spinach, etc.; and some food additives may also cause urticaria.
3, infection. Bacterial infections, toxic infections, fungal infections and parasites; insect bites such as mites, fleas, bed bugs, etc.
4, inhalation. Various pollen, dust, animal dander, fungal spores, formaldehyde, gas, etc.
5, physical and chemical factors. is caused by physical and mechanical stimulation such as cold, heat, sunlight, friction and pressure, or by certain chemical substances entering the human body.
6, mental factors and endocrine changes. Mental stress, emotional impulse, menstruation, menopause, pregnancy, etc.
7, internal medicine diseases. Such as systemic lupus erythematosus, hyperthyroidism, rheumatism, rheumatoid arthritis and gastroenteritis, etc.
8, genetic factors. Some urticaria may also be caused by genetic factors.
Picture source network
Symptoms of urticaria attack
1, Acute urticaria .
Acute urticaria is often an acute attack, with itching, wheals, rash, and may be accompanied by high fever. Some people may experience abdominal pain, severe blood pressure drop or even shock. The disease can be cured naturally within 1 to 2 weeks. , should be treated actively.
2, chronic urticaria.
The course of the disease exceeds six weeks. Chronic urticaria is a disease for which no cause is often found. Patients often develop red, swollen and itchy rashes on their body, face or limbs from time to time. The more they scratch, the more itchy and swollen they become. The number of attacks ranges from several times a day to once every few days, and the severity and onset of symptoms also vary from person to person.
Chronic urticaria, even if the cause is unknown, about 50% will be cured within 1 to 2 years. However, it is true that some urticaria recurs for a long time and affects life and work. It is necessary to take oral antihistamines for a long time and gradually reduce the dosage after the symptoms are controlled.
Picture source author
Several common special types of urticaria
1, cholinergic urticaria. is a type of rubella that people often call. It mostly occurs in adolescence. When the body temperature increases slightly due to heat, mental stress, ingestion of hot food or drinks, or after exercise, the increased blood flow stimulates the brain's temperature regulation center, excites cholinergic nerves and releases acetylcholine. Symptoms will subside when you stop exercising or calm down. In severe cases, it may take months or years for symptoms to completely subside.
2, cold urticaria .Allergic reactions caused by exposure of the human body to cold environments. Edema and wheals often occur in parts immersed in cold water or exposed to cold substances. They are more common on the face and hands, but can also affect other parts. It may cause conscious itching, and some may also cause headaches and skin flushing. , hypotension and other systemic symptoms, and severe cases may cause shock.
3, aquagenic urticaria. Where the skin comes into contact with water, wheals and itching will occur immediately or within a few minutes, and subside within 30-60 minutes. Regardless of the temperature of the water source, sweat, saliva and even tears can trigger a reaction. Applying Vaseline to the skin in advance can prevent the occurrence of wheals.
4, solar urticaria . The main symptoms are that after the skin is exposed to sunlight for a few seconds to a few minutes, itching, erythema and wheals, and angioedema rapidly appear locally, lasting for 1 to 2 hours. It is more common in women.
picture source network
5, skin scratch syndrome . is also called artificial urticaria. After scratching the skin with hands or scratching the skin with a blunt instrument, strip-like bulges will occur along the scratches, accompanied by itching, which will subside soon. It may occur alone or in conjunction with urticaria. Can occur at any age. There is often no obvious cause, but it can also be caused by drugs (especially penicillin).
6, pressure urticaria. occurs 4 to 6 hours after the skin is subjected to heavy and long-lasting compression. Diffuse, unclearly defined edematous painful plaques occur in the compressed area, involving the skin and skin tissue. It usually occurs on the palms, soles and buttocks and usually lasts for 8 to 12 hours. Sometimes it can be accompanied by chills, headache, joint pain, general malaise, etc. The pathogenesis is related to kinins.
7, angioedema. , also known as angioedema and giant urticaria, is acute localized edema, which is more common in loose subcutaneous tissue, such as eyelids, lips, foreskin, scalp, labia, etc. The skin in the edema area is tense and creamy, the boundary is not obvious, it is light red or pale, and the texture is soft, which is non-pitting edema.
Picture source network
What should I do if I get urticaria?
1, Most people’s intuitive reaction to itchy skin is to scratch it quickly with their hands, but you may not know that doing so will not relieve the itching, and may make it more itchy the more you scratch it. The main reason is that when you scratch a local area, the local temperature will increase, causing the blood to release more histamine ( allergen ), which will worsen the condition.
2, Some people use hot compresses. Although hot compresses can temporarily relieve the local area, it is actually another kind of irritation, because heat will tense blood vessels and release more allergens. For example, some people soak in hot water in winter. Being in a hot spring or bathtub, or being overly warm and wrapped in a heavy quilt may cause urticaria.
3, Eat less seafood, mutton and other foods, eat more fruits and vegetables, and avoid drinking alcohol and irritating foods. Taboos are not recommended, but if certain foods can trigger or aggravate urticaria, then the food may be allergic and should be avoided temporarily.
4, should actively go to the hospital for treatment; avoid external use of hormone drugs. Unless the urticaria is particularly severe, long-term oral hormone and immunosuppressant treatment is not suitable, especially for chronic urticaria.
Editor: Lu Fanying
