Why does chicken pox appear?

Classification: medical and health >; & gt pediatrics

Problem description:

How is the treatment?

Analysis:

chickenpox

Chickenpox is an acute infectious disease caused by the primary infection of varicella zoster virus. It mainly occurs in infants, characterized by fever, and red maculopapules, herpes and scab rash appear in batches.

[etiology]

The virus belongs to herpesviridae, and it is spherical with a diameter of 150 ~ 200 nm. Double-stranded DNA in the center and icosahedral nucleocapsid outside. There is a lipoprotein envelope on the surface of capsid, which contains complement binding antigen and does not contain hemagglutinin and hemolysin.

There is only one serotype of this virus, which can propagate in human embryonic fibroblasts and thyroid cells, resulting in focal cytopathy, with eosinophilic inclusions and multinucleated giant cells in the nucleus. Man is the only host.

VZV is weak in viability, not resistant to high temperature, unable to survive in scabs, and easily inactivated by disinfectants. But it can survive for 8 years in herpes fluid at -65℃.

Viruses first propagate in the upper respiratory tract, a small amount of viruses invade the blood and propagate in the mononuclear phagocytic system, and then a large number of viruses enter the blood circulation, forming secondary viremia, invading the skin and internal organs, causing diseases.

[epidemiology]

Chickenpox is highly contagious. The patient is the main source of infection, which is contagious from 1 ~ 2 days before eruption to 5 days after eruption. Children who come into contact with herpes zoster patients will also get chicken pox because they have the same cause. The main route of transmission is respiratory droplets or direct contact infection. You can also contact contaminated materials to receive dyes.

The disease mainly occurs in winter and spring, mainly in children aged 2 ~ 10. People are generally susceptible, but once they get sick, they can be immune for life.

(1) Infection source Chickenpox patients are the main source of infection, which is contagious from 1 ~ 2 days before the outbreak of chickenpox to when the rash is dry and crusted. Chickenpox can also occur in children who are easy to contact with herpes zoster patients, but it is rare.

(2) The route of transmission is mainly through droplets and direct contact. It can also be transmitted indirectly through healthy people in a short distance and in a short time.

(3) Susceptible people are generally susceptible. But preschool children have the most diseases. Babies less than 6 months old are less likely to get sick due to maternal antibodies. Chickenpox during pregnancy can infect the fetus. Persistent immunity can be obtained after illness, but herpes zoster can occur.

(4) Epidemic characteristics can occur all year round, especially in winter and spring. The disease is highly contagious, and about 90% of susceptible people get sick after contact with patients, so children's collective institutions such as kindergartens and primary schools are easy to cause epidemics.

[Pathogenesis and Pathoanatomy]

The virus invades from respiratory tract, grows and reproduces on mucosa, then enters blood and lymph, and proliferates again in reticuloendothelial cell system. Virus invasion into the blood causes secondary viremia and systemic diseases, mainly in the skin, and the appearance of rash is related to intermittent viremia. Then there was a specific immune response, viremia disappeared and symptoms were alleviated. When the immune function is low, it is easy to have serious systemic chickenpox. In some cases, lesions may involve internal organs. Some viruses are introduced along sensory nerve endings. Long-term latent infection is formed in the posterior root ganglion of spinal nerve. When the body's immunity drops (such as suffering from malignant tumor, stimulated), the virus is activated, leading to neuritis, which goes down the nerve to the corresponding skin segment, causing cluster herpes and neuralgia, called herpes zoster.

Chickenpox lesions are mainly in epidermal spinous cells. Cell degeneration and edema form cystic cells, and cystic cells liquefy and infiltrate tissues to form blisters, with congestion, mononuclear cells and multinucleated giant cells infiltrating around and at the base, and there are eosinophilic inclusions in multinucleated giant cells. Blisters contain a lot of viruses. It is transparent at first, then it becomes turbid due to epithelial cell shedding and leukocyte invasion, and it can become pustule after secondary infection. Skin damage is shallow, leaving no scar after scabbing. Mucosal herpes is easy to form ulcers and heal. Individual cases of chickenpox may involve lung, esophagus, stomach, small intestine, liver, adrenal gland and pancreas, causing local congestion, bleeding, inflammatory cell infiltration and local necrosis. Inflammatory cell infiltration, hemorrhage, focal necrosis and fibrosis can occur in the ganglion involved in herpes zoster.

[Clinical manifestations]

The incubation period of the disease is about 14 ~ 15 days. The onset is acute, mild and moderate fever with rash, which first occurs in the compressed parts of scalp and trunk and presents centripetal distribution. During the eruption period of 1 ~ 6 days, rashes appeared in batches. The skin lesions showed the evolution process of tiny red maculopapular rash → accessory rash → symptom rash → asymptomatic, and there was no sign of fatigue after asymptomatic. Water scar is obviously painful. Scratching infection can leave a slight dent. The weak can have high fever, and about 4% adults can have disseminated chickenpox and chickenpox pneumonia.

It is more common in children aged 1- 10, with an incubation period of 2-3 weeks. The onset is more acute, and there may be precursor symptoms such as fever, headache and general burnout. A rash appeared within 24 hours of onset, and immediately turned into a round tension blister the size of rice grain to pea, with obvious redness and swelling around it, and the center of the blister was in the shape of umbilical fossa. After about 2-3 days, the blister dried up and scabbed, and the scab fell off and healed, leaving no scars. Skin lesions are centripetal, starting from the front face and then appearing in the trunk and limbs. The number varies with the trunk, followed by the face and head, with fewer limbs and fewer palms and soles. Mucosa is often invaded, which is found in the mouth, pharynx, conjunctiva, vulva, * * and so on. Skin lesions often appear in batches, so papules, blisters and scabs often coexist, and the course of disease lasts for 2-3 weeks. If the child's resistance is low, the lesions can spread systematically, forming disseminated chickenpox. The clinical manifestations of chickenpox are: bullous chickenpox, hemorrhagic chickenpox, neonatal chickenpox, adult chickenpox and so on.

It needs to be differentiated from smallpox: smallpox has a serious systemic reaction, that is, it has a high fever of 39-40 degrees at the beginning, followed by a rash, with obvious umbilical depression in the center of the skin lesion and enlarged face, leaving a sunken scar after healing. Pay attention to the difference between impetigo and papular urticaria.

[diagnosis]

[therapy]

There is no specific treatment for this disease, mainly symptomatic treatment to prevent secondary infection of the skin, keep it clean and avoid itching. When herpes breaks or secondary infection occurs, 1% methyl violet can be applied locally, and calamine lotion can be applied to those who have not broken. Early use of 10mg/kg/ day or 8mg/kg/ day acyclovir for 5 ~ 7 days, or adding interferon, can inhibit virus replication. Daily intramuscular injection of vitamin B 12500 ~ 1000 ug also has certain curative effect. Effective antitoxin can be used when there is secondary infection, and hormone should not be used for chickenpox to avoid spreading the virus.

[Prognosis]

[prevention]

The prevention of this disease focuses on managing the source of infection and isolating patients until all symptoms break out. For the highly susceptible population with contact history, varicella-zoster immunoglobulin or high titer herpes zoster immune plasma can be injected within 3 days to reduce the risk of illness.

Isolate the patient until 7 days after all rashes scab or rash. Its pollutants and utensils can be disinfected by boiling or exposure. The susceptible population exposed to chickenpox should be kept for 3 weeks. Early use of gamma globulin (0.4-0.6ml/kg) or 5ml of herpes zoster immunoglobulin can significantly reduce the incidence of chickenpox and relieve symptoms. The live varicella virus vaccine developed in recent years is effective for the prevention of normal susceptible children.

References:

Prevention and treatment of chickenpox

Chickenpox is an eruptive acute respiratory infectious disease caused by varicella virus, which mainly occurs in children aged 2-6 years, and occasionally occurs in adults and infants. It is mainly transmitted by air droplets through the respiratory tract, and can also be transmitted through clothes, utensils and toys because of contact with blister meat in children's herpes, which is highly contagious. It can happen all year round, especially in winter and spring.

It takes 2 ~ 3 weeks for children to develop symptoms after being infected with varicella virus. Generally, patients have a fever for one day, accompanied by headache, anorexia, crying, restlessness, general malaise or cough, and then a rash occurs, which is mostly distributed in the head, face, trunk and armpit, with few limbs, palms and soles, showing centripetal distribution. At the beginning, the skin appears bright red macula or maculopapule with the size of rice grains to beans, and within 24 hours, round or oval blisters are formed, with redness around them, and the blisters are easy to rupture and fester. After 3 ~ 5 days, the blister gradually dries, first shrinks from the center, then scabs, and after several days or 2 ~ 3 weeks, the scabs completely fall off and heal, generally leaving no trace. At the onset, conjunctiva, oral mucosa and pharyngeal mucosa can be damaged. Lifelong immunity can be obtained after illness. A few children have weak resistance and poor immune function, and may have hemorrhagic blisters and secondary bacterial infections, which may lead to encephalitis, pneumonia, myocarditis or other organ diseases.

Children with chickenpox are generally mild, with few complications, and often recover naturally within 7 ~ 10 days without special treatment. But be careful to prevent infection. Stay in bed during fever and rash, give sick children plenty of water, provide nutritious and digestible food such as milk, eggs, fruits and vegetables, and avoid eating spicy fish and shrimp. Prevent colds, especially don't blow; Wash your hands and face frequently, change clothes frequently and keep your skin clean; Pay attention to the cleaning and disinfection of clothes and utensils and pay attention to hygiene. The room should be ventilated frequently, and the temperature and humidity should be appropriate. Cut the nails short to prevent the child from scratching the rash and causing infection. If itching is serious, you can wipe the furnace dry stone lotion to stop itching, or take chlorpheniramine and other drugs; Herpes can be coated with gentian violet, and some anti-inflammatory ointment can be applied locally to existing infections, and berberine and sulfonamides can be taken when necessary; Do not use ointment such as Fusong and prednisone to avoid chicken pox all over the body. Children with persistent high fever, cough, headache, chest pain or herpes, red and turbid blister fluid and diffuse abscess, cellulitis or lymphadenitis should be sent to hospital for treatment.

In order to prevent chicken pox infection, children should be isolated until the rash scabs. Children who have been exposed to chickenpox for 3 weeks are best isolated, and those who are weak can be injected with gamma globulin within 4 days after exposure. Try to take children to public places as little as possible during the epidemic.

Chickenpox is an acute infectious disease caused by varicella-zoster virus. It is common in children and highly contagious. The main route of transmission is droplets. Its characteristic is that the rash first appears on the trunk, then spreads to the face, and finally reaches the limbs, showing a polymorphic rash: macula, papule, herpes zoster and scab rash. Patients with chickenpox should be strictly isolated, rested, and the diet is nutritious and easy to digest. Wet the damaged skin with 2%-5% sodium bicarbonate, and don't scratch it with your hands. Apply antibiotic ointment to purulent skin. Antiviral therapy for people with immunodeficiency. Adrenal cortical hormone is prohibited.

Chickenpox (herpes zoster)

What is chicken pox?

This disease is a highly contagious disease caused by varicella zoster virus. Almost everyone suffers from this disease, usually in childhood. If you are not sick in childhood, you are still sensitive and can be infected in adulthood.

How to infect?

Contact with infected patients. The virus spreads through the air because of the patient's cough and sneezing, and can also be infected by touching the cloth and bedding used by the patient. The scab in the late stage of the disease is not contagious.

What are the symptoms?

Low fever, headache, loss of appetite. 1-2 days later, itchy blisters appeared on the skin, usually starting from the trunk and then spreading to the face and other parts of the body. In severe cases, blisters may appear on the head, armpits, eyelids and mouth, and then rupture and scab. The symptoms of adults are often more serious than those of children.

When do the symptoms appear?

Generally, it is 2 weeks after exposure to the virus, or 1 1-2 1 day.

How long is the infection period?

65438+ 0-2 days before blisters appear to 5 days after the first blisters appear. When all blisters are dry, they can be considered as non-infectious.

Is it necessary to isolate?

Yes After the first appearance of blisters, or until all blisters are dry and scabbed, patients should work or go to school in isolation for 5 days.

How to treat it?

Usually no special treatment is needed, and calamine lotion is often used to relieve itching. If the effect is not good, you should see a doctor.

Is there a preventive vaccine?

Yes Chickenpox vaccine has been approved for use in the United States. Consult a doctor.

How to avoid infection?

Avoid contact with patients, because early diagnosis of chickenpox is almost impossible. If there is danger, you can get a vaccine. Patients should be isolated until 5 days after the first blister appears, or until all chickenpox dries and crusts.

chickenpox

(chicken pox)

Chickenpox is a highly acute infectious disease in children, which occasionally occurs in adults. Have lifelong immunity. It is a primary infection caused by various herpes DNA viruses, namely varicella-zoster virus. It is characterized by fever and red maculopapules, herpes and scabs all over the body.

Etiology and pathogenesis

Varicella-zoster virus (VZV) is brick-shaped with a diameter of 150-200nm. Its nucleic acid is DNA, which has a three-dimensional symmetrical capsid and reproduces in cells. Patients are the only source of infection. VZV exists in respiratory secretions, herpes and blood of patients, and is transmitted by droplets or direct contact with blister fluid. As we all know, VZV virus can spread through medical devices. VZV mainly invades through respiratory tract, grows and reproduces on mucosa, then enters blood and lymph, and reproduces in reticuloendothelial cells for the second time, causing viremia and systemic diseases. The main damage site is the skin, occasionally involving internal organs.

clinical picture

treat cordially

Children should be isolated as soon as possible until all rashes scab. Children who have been exposed to chickenpox should be isolated for 3 weeks.

Systematic therapy

Mainly to strengthen nursing to prevent secondary infection and complications. Stay in bed during the fever period, and give adequate nutritional support and drinking water supply. Clinical symptomatic medication is the main method. People with high fever can be given calamine lotion for external use to relieve itching. Those with blisters can be coated with 2% gentian violet solution. If there are complications such as diffuse pustules, cellulite or acute lymphadenitis, broad-spectrum antibiotics should be used. Severe patients can be injected with gamma globulin intramuscularly. Do not use corticosteroids to prevent the spread and aggravation of chickenpox.

Patients with disseminated varicella with low immunity, neonatal varicella or varicella pneumonia, encephalitis and other serious cases should be treated with antiviral drugs as soon as possible. Cytarabine10 mg/kg d, intravenous drip. Or acyclovir 5- 10mg/kg, every 8 hours 1 time, with a course of treatment of 5-7 days, or add interferon A to inhibit virus replication, prevent virus spread, promote skin lesion healing, accelerate disease recovery and reduce mortality.

How does chickenpox happen?

Chickenpox usually occurs in children aged 2 ~ 10, and it is an acute and highly contagious infectious disease. Chickenpox usually occurs in winter and spring, and often causes epidemic in kindergartens or primary schools.

The pathogen of varicella is varicella-zoster virus, which exists in patients' blood, herpes serosa and oral secretions. It is mainly transmitted by droplets through the respiratory tract, and it may also be infected by contact with dust, clothes and utensils contaminated by viruses. In other words, healthy children may be infected and get sick if they often play, talk and have close contact with children with chickenpox. Therefore, once you have chickenpox, you should pay attention to isolation. Before you are completely cured, don't go to kindergarten or school. Even children who have had contact with chickenpox patients should be observed in isolation for 2 ~ 3 weeks. Because you don't get sick immediately after being infected with the virus, you usually need an incubation period of 14 ~ 17 days, which can reach 3 weeks for the elderly.

Chickenpox is highly contagious, and patients are the only source of infection. About 90% of children who come into contact with it will get sick. In addition, it is contagious from the day before the onset to the dry scab of all rashes.

The onset is more acute, and there may be systemic symptoms such as fever, burnout and loss of appetite. Adults are more obvious than children, and rashes usually appear within 1 ~ 2 days. It first occurs in the trunk and gradually extends to the head, face and limbs, showing a centripetal distribution, that is, there are more trunks, fewer facial limbs and fewer palms and soles. At first, it was a small red pimple, and after a few hours, it turned into a blister the size of mung bean, and the surrounding area was flushed. Blisters are clear water droplets at first, with thin and fragile walls and itching. After 2 ~ 3 days, the scab shaft healed without leaving scars. Within 3 ~ 5 days of onset, rashes appear in batches, so papules, blisters, scabs and other skin lesions in different periods can occur at the same time, and the course of disease is about 2 ~ 3 weeks.

Oral cavity, conjunctiva, pharynx, vulva and other mucous membranes are occasionally damaged, often forming ulcers accompanied by pain.

The more reckless the better. As long as it conforms to the general rash law, it is normal to have a rash more or less. If the blister is scratched and secondary bacterial infection occurs, skin gangrene may occur and even septicemia may occur. In addition, a few patients may have complications such as varicella pneumonia, encephalitis, myocarditis and fulminant purpura.

Traditional Chinese medicine believes that this disease is caused by exogenous heat toxin and damp heat accumulated in the skin.

Can chickenpox leave a scar?

Chickenpox occurs in a wide range, extending to the head and face, appearing in batches and in large quantities, so some people worry that it will leave scars and affect the appearance. This kind of worry is unnecessary.

Generally speaking, the occurrence and regression of chickenpox are carried out according to the natural course of disease. Even if the blister is broken to form a rotten surface, it will heal quickly without leaving scars after healing. But if you don't pay attention to keep your skin clean, it's easy to get bacterial infection or even gangrene after repeated scratching, and there will be scars after healing. Because the damage site of simple chickenpox is very shallow and can't reach the dermal tissue, if it is combined with bacterial infection, it will be destroyed downwards, leading to scar formation.

It can be seen that chickenpox will not leave scars. However, there are several special types of chickenpox in clinic, which should be paid attention to.

(1) Bullous chickenpox is only found in children under 2 years old. It is a large blister with a size of 2 ~ 7 cm that appears in batches. After bursting, a rotten surface is formed, but it heals quickly.

(2) Hemorrhagic varicella blisters are bloody, with high fever and severe systemic symptoms. It is common in patients with malnutrition, malignant lymphoma and leukemia treated with immunosuppressants and corticosteroids.

(3) Newborn chickenpox is usually infected by the mother during childbirth, with mild symptoms, but it can also cause systemic damage and lead to death.

(4) The symptoms of chickenpox in adults are more serious than those in children. Long prodromal period, high fever, severe systemic symptoms, many rashes and itching.

Although the above special types are rare, once they occur, we should strengthen nursing to prevent secondary infection. Otherwise, it is not only a problem of leaving scars, but also serious complications such as pneumonia, encephalitis, myocarditis and nephritis, and even life-threatening.

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