Category: Medical/Disease gt; gt; Dermatology

Problem description:

After the summer, the child often feels itchy, but he scratches it a few times A red envelope will appear, just like a mosquito bite, and then many bumps similar to this will appear on the body. After taking the "Karitan" anti-allergic medicine, the symptoms will disappear, but they will recur after two days. , the child is usually in good health, and I pay attention to what she eats, but I don’t know why she keeps getting attacks?

Analysis:

Urticaria (Urticaria), commonly known as wheals, is a common skin disease. Various factors cause temporary inflammatory congestion and large amounts of fluid exudation in the blood vessels of the skin and mucous membranes. Cause local edematous damage. It occurs and subsides rapidly, with severe itching. There may be fever, abdominal pain, diarrhea or other systemic symptoms. It can be divided into acute urticaria, chronic urticaria, angioedema and papular urticaria.

Urticaria is a common allergic skin disease. When exposed to allergens, red patches of different shapes and sizes will appear in unspecified parts of the body. These produce Itching will occur in the plaque area. If the exposure to the red allergen is not stopped and treated, the rash and itching will intensify.

Urticaria classification and urticaria symptoms:

1. Urticaria in children

Urticaria is not only a common disease in adults, but also a common disease in children. sick. The characteristics of urticaria in children are that it is mostly caused by allergic reactions. The most common and suspected causes are food first, followed by infection. The causes of urticaria vary depending on age and diet. For example, if babies are mainly fed breast milk, milk, and dairy products, the causes of urticaria are mostly related to additives in milk and dairy products.

As age increases, infants and young children begin to eat more complementary foods. At this time, eggs, meat floss, fish floss, juice, vegetables, and fruits can all become causes of allergies. Preschool and school-age children often like to eat snacks. There are many types of snacks and dinner foods, so the chance of food allergies increases, such as nuts, fish, crabs, shrimps, peanuts, eggs, strawberries, apples, plums, citrus, All kinds of cold drinks, drinks, chocolate, etc. may be the cause of allergies.

Children aged 2-7 years old lack the ability to self-govern. When they go outdoors, in the wild, in the woods, or under street lights in the evening, they are often bitten by insects, or come into contact with pollen, dust, mites, and the fur of pets such as cats and dogs. When exposed to them, they can easily become the cause of allergies. Children in childhood and early childhood have low resistance and are prone to various infections. Therefore, diseases such as purulent tonsillitis, pharyngitis, enteritis, and upper respiratory tract infections can become inducing factors of urticaria throughout the year. Older children and teenagers are more likely to be allergic to drugs, especially penicillin, causing urticaria.

Urticaria in children is induced by drugs, cold or hot sun exposure, mental stress, etc. Urticaria associated with systemic diseases is far less common than in adults.

Judging from the course of the disease, urticaria in children is mostly acute urticaria. However, as age increases, allergic eczema and asthma in children and adolescents worsen, or they take drugs (such as penicillins and sulfonamides). , the urticaria caused can gradually change from acute urticaria to chronic urticaria. Chronic urticaria and drug-induced urticaria are more common in adults than in children.

2. Cholinergic urticaria

It mostly occurs in adolescence and appears after exposure to heat (hot drinks, hot water baths), emotional excitement and exercise. The rash is characterized by small wheals of 1 to 3 mm in size, with redness around them, mostly on the trunk and proximal limbs, and itching. Some patients are accompanied by gastrointestinal symptoms, such as abdominal pain, diarrhea, etc.

3. Chronic urticaria

It is a disease for which the cause is often not found. Patients often develop red, swollen and itchy patches on the body, face or limbs from time to time. The rash often becomes more itchy and swollen the more you scratch it. The number of attacks ranges from several times a day to once every few days.

4. Cold urticaria

Acquired cold urticaria: It is the most common physical urticaria and can occur suddenly at any age. After the skin is exposed to cold wind, cold water, etc., itchy edema and wheals may occur locally within a few minutes, which may last for 30 to 60 minutes and will be relieved after keeping warm.

Hereditary cold urticaria: It is a dominant inheritance and is more common in women. It begins in infancy and lasts throughout life. Generalized wheals appear a few hours after exposure to cold, with a burning sensation but not itching, and can last for 48 hours. It is also accompanied by chills, fever, headache, joint pain and increased fold cells.

5. Papular urticaria

Papular urticaria is an itchy skin disease that commonly occurs in infants and children. The skin lesions are often round or spindle-shaped wheal-like lesions, with pinhead to bean-sized blisters at the top, scattered or clustered. It usually occurs on the extensor sides of the limbs, trunk and buttocks. Generally, the skin lesions will subside on their own after a few days to a week, leaving temporary pigmentation spots. Skin lesions often appear in batches one after another and last for a period of time. This disease causes severe itching and may cause pyoderma due to repeated scratching. The cause of this disease is relatively complex, and most believe it is related to insect bites, such as fleas, lice, mites, midges, bedbugs, and mosquitoes.

6. Acute urticaria

Acute urticaria is a localized edema reaction caused by the dilation of small blood vessels in the skin and mucosa and increased permeability caused by a variety of causes. In urticaria, the entire skin inflammatory system is activated. Therefore, in addition to the well-established histamine, other transmitters also play a synergistic role in the pathogenesis of acute urticaria.

Acute eczema has a rapid onset and polymorphous rash. The main manifestations are papules, papules, blisters, erosion, exudation, scabs, etc. on the basis of erythema and edema. The extent of the damage is unclear. In severe cases, it can spread throughout the body and cause severe itching.

Subacute eczema is after the acute inflammation is relieved. The rash is mainly composed of small papules, scales and scabs, with only a small amount of papules, blisters and erosion; the skin lesions are relatively localized and the itching is still severe.

Chronic eczema is transformed from repeated attacks of acute eczema and subacute eczema. The symptoms include rough skin, scratches, scabs, soaked hypertrophy, partial lichenification, pigmentation, and scattered papular herpes on the periphery.

Scrotal eczema is a common skin disease limited to the scrotum. Its causes are complex and may often be related to local uncleanness, tight or airtight vaginal tissue (chemical fibers) or allergies. It is related to certain physical and chemical factors, and may also be related to mental factors. The most prominent manifestations of the disease are unbearable local itching of the scrotum, scratches left by local factors, mild skin erosion or infiltration and hypertrophy, and skin wrinkles becoming deep and wide. Scratching due to extreme itching leads to more itching, and the course of the disease is longer, which can affect sleep and work.

7. Peptone urticaria: (acute peptone allergic urticaria)

Under normal circumstances, peptone decomposed from food proteins is easily digested and is not or rarely inhaled into the blood, but When you eat too much at one time (eating too much pork and seafood), are agitated and drink a lot of alcohol at the same time, peptone can be absorbed into the bloodstream through the intestinal mucosa and cause illness. Skin congestion, redness, wheals, headaches, and fatigue will occur. The course of the disease is very short, lasting only 1 to 2 days, and most of them disappear within 1 to 4 hours. It is an antigen-antibody reaction, and its pathogenic mediator is histamine.

8. Solar urticaria

The main manifestations are that after the skin is exposed to sunlight for a few seconds to a few minutes, itching, erythema, wheals, and angioedema rapidly appear locally, lasting for 1~ 2 hours. It is more common in women.

9. Skin scratch disease

Also known as 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).

10. Serum disease urticaria

It is caused by drugs (penicillin, furazolidine, etc.), vaccines or foreign blood. The most common skin lesions are wheals, especially multi-annular wheals, and toxic erythema and erythema nodosum-like symptoms may also be present.

Patients also have symptoms of serum sickness or serum sickness-like reactions such as fever, joint pain, and lymphadenopathy. There may still be heart and kidney damage. It is an antigen-antibody complex reaction.

11. Pressure urticaria

Occurs 4 to 6 hours after the skin is subjected to heavy and long-lasting pressure, and diffuse, unclearly defined edematous painful spots occur in the compressed area. lumps, involving 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, and general malaise. The pathogenesis is related to irritation.