chicken pox
Introduction
Introduction to chickenpox Varicella is a primary infection caused by varicella-zoster virus. It is an acute infectious skin disease characterized by mild systemic symptoms and rash, papules, blisters and pimples. . More common in children, it is highly contagious, easy to cause a small area of prevalence, and can be immunized for life. basic knowledge The proportion of sickness: 0.16% Susceptible people: no special people Mode of infection: droplet spread contact spread Complications: impetigo pneumonia myocarditis hypothalamic syndrome
Cause
Chickenpox cause
Causes:
Varicella-zoster virus infection:
The varicella-zoster virus and herpes simplex virus belong to the herpesvirus subfamily. The virus is latent in the host for a long time. The disease manifests as herpetic damage of the whole body or local skin mucosa. It is easy to relapse and its common feature is chickenpox-band. Herpes zoster virus is a spherical virus particle with a diameter of about 150-200 nm, with a bilayer of lipoprotein envelope. The varicella-zoster virus has only one serotype. Human is the only natural host, varicella-zoster virus VZV. It has weak resistance to the in vitro environment and quickly loses its activity in the dry herpes crust. However, in herpes liquid, it can be stored at -65 °C for a long time. The virus can be cultured in vitro using human embryonic fiber cells, but not in It grows in general animal tissues such as chicken embryos.
Susceptible people:
It is generally susceptible, but preschool children have the most morbidity. Infants within 6 months have fewer maternal antibodies because of their maternal antibodies. They can contract the fetus during pregnancy and get long-lasting immunity after the disease, but can develop herpes zoster.
Source of infection:
The chickenpox is the main source of infection. It is contagious from 1 to 2 days before the rash is caused by the rash and dry and crusted. The susceptible children are exposed to herpes zoster, and chickenpox can also occur, but it is rare.
Pathogenesis
The virus invades the epithelial cells of the upper respiratory tract and then enters the bloodstream. After reaching the white blood cells, it will enter the bloodstream and form viremia. The virus is scattered in various organs and tissues of the whole body, causing systemic diseases. The skin lesions are mainly the spinous cell layer. Cell edema degeneration, nuclear division into multinucleated giant cells, nuclear eosinophilic inclusions formed in the nucleus, followed by cell liquefaction, the formation of atrial thin wall blister, early herpes liquid specimens observed under electron microscopy revealed a large number of viruses, due to increased inflammatory cells And mixed with exfoliated tissue cell debris, herpes liquid can gradually become cloudy, can also be pustular-like appearance, around the herpes and the lower dermal tissue congestion, forming a linear blush around the base of herpes, the virus in the late herpes liquid The content is reduced, because the lesion is superficial, the scar is not left after healing, and the mucosa of the eyes, nose, mouth, and pharynx may also form herpes, and it is easy to ulcerate, but it is easy to heal, and at the same time, the chickenpox patient Allergic inflammation can occur in a variety of tissues, including the lungs, liver, spleen, adrenal gland, gastrointestinal tract, heart muscle, pancreas , vascular endothelium and brain tissue, etc., the lung tissue of patients with varicella pneumonia is extensive interstitial inflammation, scattered in the focal necrosis area; alveolar bleeding, alveolar and bronchioles containing fibrinous exudate, Red blood cells and multinucleated giant cells with inclusion bodies, mononuclear cells infiltrated around the interstitial lung and bronchioles. In patients with varicella encephalitis, degeneration and necrosis of the brain tissue, punctiform hemorrhage, and demyelinating changes around the interstitial vessels And infiltration of lymphocytes around the cerebrovascular.
Epidemiology
Chickenpox is highly contagious, and the patient is the main source of infection. It is contagious from 1 to 2 days before the rash to 5 days after the rash. Children with herpes zoster can also develop chickenpox because of the same cause and the main route of transmission. It is a respiratory droplet or direct contact with infection, and it can also be exposed to contaminated objects for reception.
The disease is mainly caused by winter and spring, mainly for children aged 2 to 10 years old. The population is generally susceptible, but once a disease can be immunized for life.
1. The transmission route is mainly spread by droplets and direct contact, and can be transmitted indirectly through healthy people in a short distance and in a short time.
2, epidemic characteristics can occur throughout the year, more common in winter and spring, the disease is highly contagious, susceptible to contact with patients about 90% of the incidence, so kindergartens, primary schools and other children's collective institutions are likely to cause epidemics.
Prevention
Chickenpox prevention
The patient should be isolated from the respiratory tract until all herpes dry and scarred. In the collective institution, the susceptible person should be inspected for 3 weeks (can be observed from the 11th day after the contact), and the patient's respiratory secretions or rash contents Contaminated air, clothing and utensils should be disinfected by ventilation, ultraviolet radiation, exposure, boiling, etc. Foreign reports of immunodeficiency, vaccination-specific immunoglobulin (VZIG) prevention in pregnant women and mothers with varicella Placental globulin or varicella recovery serum (accumulation of varicella disappeared within 1 month) is limited to those who are infirm or the original chronic disease; the effect of placental globulin is not certain.
Because the symptoms of varicella are mild, it is considered that VZV vaccine prevention is not needed in the past. It is later found that leukemia patients are prone to varicella complications. Therefore, the use of VZV vaccine for leukemia patients has achieved satisfactory results. In recent years, due to concurrent group A streptococcal infection. Children with chickenpox are critically ill and have a high mortality rate. Therefore, in 1995, the United States introduced infants who did not have chickenpox. Children, adolescents and adults must receive VZV vaccine to prevent chickenpox.
[Control of chickenpox]
Chickenpox is a rash-like acute respiratory infection caused by varicella virus. It is more common in children aged 2-6 years. It occurs occasionally in adults and infants. It is mainly transmitted through the respiratory tract through airborne droplets. It can also be caused by contact with herpes in herpes. It is transmitted through clothes, utensils and toys. It is highly contagious and can be affected all year round. It is more common in winter and spring.
After babies are infected with varicella virus, symptoms will appear after 2 to 3 weeks of incubation. Usually, they have a fever for a day, accompanied by headache, anorexia, crying, irritability, general malaise or coughing. Then there is a rash, mostly scattered. On the head and face, torso and underarms, it occurs in the limbs, palms, and soles of the feet. It is distributed in a centripetal manner. When the skin starts to appear, the skin appears to be red-colored rash or maculopapular rash of the size of the beans, forming a round shape within 24 hours. Or oval blisters, surrounded by redness, blisters are easily broken and ulcerated. After 3 to 5 days, the blisters gradually dry, first shrinking from the center, then crusting, and then after a few days or 2 to 3 weeks, the scars completely fall off and heal Generally, no traces are left. Conjunctiva, oral and pharyngeal mucosa, vaginal mucosa can be damaged when the disease occurs. Lifetime immunity can be obtained after the disease. A small number of children have weak resistance, poor immune function, hemorrhagic vesicles and secondary bleeding. Sexual bacterial infections can cause encephalitis, pneumonia, myocarditis or other organ diseases.
The condition of children with chickenpox is generally mild, with few complications, no special treatment, and can be cured naturally within 7 to 10 days, but care should be taken to prevent infection, fever and rash should rest in bed, give more sick children Drink water, and supply nutritious, easily digestible foods such as milk, eggs, fruits, vegetables, etc., avoid eating spicy fish and shrimp and other foods; prevent colds, especially do not blow; often wash your hands, wash clothes, keep your skin clean; Pay attention to the cleaning and disinfection of clothes and utensils, pay attention to hygiene, the room should be ventilated frequently, the temperature and humidity should be appropriate, cut short nails, avoid the infection caused by rash in children, if itching is serious, you can wipe the dry stone lotion to relieve itching. Take chlorpheniramine and other drugs; herpes rupture can be coated with gentian violet, existing infections can be partially applied with some anti-inflammatory ointment, if necessary, can take berberine, sulfa drugs; avoid using a relaxed, strong pine-like ointment, So as not to cause systemic varicella, such as persistent high fever, cough, headache, chest pain or herpes dense, red and red, blister opacity and diffuse abscess, cellulitis Children lymphadenitis, you need hospital treatment.
In order to prevent chickenpox infection, the child should be isolated until the rash is completely scarred. It is best to isolate the child who has been exposed to chickenpox for 3 weeks. The infirm can inject gamma globulin within 4 days after the exposure. Take your child to a public place.
Chickenpox is an acute infectious disease caused by varicella-zoster virus. It is more common in children and is highly contagious. The main route of transmission is droplets. It is characterized by rash on the torso, then spread to the face, and finally reaches the limbs. Sexual rash: rash, pimples, vesicular rash, pityriasis, varicella patients should be strictly isolated, rest, eat nutritious and digestible diet, skin damage with 2%-5% NaHCO3 wet compress, taboo hand grasp, suppuration smear Antibiotic ointment, antiviral treatment for immunodeficiency, and banned adrenocortical hormone.
[Food Principles for Chickenpox Patients]
(1) It is advisable to give a digestible and nutrient-rich liquid and semi-liquid diet. It is advisable to drink mung bean soup, silver flower dew, wheat soup, porridge, noodles, and dragon egg noodles.
(2) Avoid greasy foods such as greasy, ginger, and chili.
(3) It is advisable to drink more water and beverages.
Complication
Chickenpox complications Complications, impetigo, pneumonia, myocarditis, hypothalamic syndrome
(A) secondary infections of the skin are most common such as impetigo, cellulitis and so on.
(B) thrombocytopenia with skin, mucosal bleeding, severe visceral bleeding. Including adrenal hemorrhage, poor prognosis.
(C) varicella pneumonia is not common in children, clinical symptoms recover quickly, X-ray changes often last 6 to 12 weeks, occasional death reports.
(4) Myocarditis, pericarditis, endocarditis, hepatitis, glomerulonephritis, arthritis and orchitis have been reported in a few cases. Laryngeal injury can cause edema, and severe cases lead to respiratory distress.
(5) Nervous system encephalitis often occurs several days after the rash, the incidence rate is <1, the mortality rate is 5%~10%, and those with cerebellar symptoms such as ataxia, nystagmus, trembling, etc. are more likely to have convulsions and coma. The prognosis of patients with brain symptoms is good. 15% of survivors have epilepsy, sequelae such as mental retardation and behavioral disorders. Other neurological complications include: Ge-Bar syndrome, transverse myelitis, facial nerve spasm, with temporary visual loss. For optic neuritis and hypothalamic syndrome, Reye syndrome accounts for 10% of cases after varicella.
Symptom
Varicella symptoms common symptoms varicella scarring varicella-like rash itch rash irritability restless blush hairpin low heat pustule fever
1. Clinical practice of chickenpox
The incubation period is about 12 to 21 days, with an average of 14 days. The incidence is more urgent. There are low or moderate fever in the prodromal period, headache, myalgia, joint pain, general malaise, loss of appetite, cough and other symptoms; several hours after onset, or Within 1 to 2 days, a rash occurs, and the entire course is as short as one week and as long as several weeks.
2. Characteristics of chickenpox rash
The number of varicella rashes is high, ranging from hundreds to thousands. It usually appears on the face, scalp and trunk. The distribution is centripetal, with hairline, chest and back, less limbs, and occasional palm soles. The mucous membranes of the nose, throat, mouth, vulva and other parts can also be rash. The rash is accompanied by different degrees of systemic symptoms, but it is often relieved before the rash. The fever generally declines to normal with the rash stop. The rash is itchy, sometimes it is irritated by the itch, the rash on the mucous membrane is easy to break into ulcers, often accompanied by pain, the number of rash is more severe, the chicken rash develops rash, pimples, herpes and crusting Four stages, initially red spotted rash, turned into deep red papules after a few hours, and then became herpes after a few hours. Typical herpes is oval, thin and easy to break, surrounded by redness, normal skin between herpes The blister fluid gradually becomes cloudy after being transparent, and even has a pustular appearance; it can also form a typical pustule due to secondary purulent infection caused by the patient's scratching, and thus causes systemic symptoms to aggravate, if no purulent infection occurs. , from herpes One to two days after the formation, it began to dry up from the center of herpes. After a few days, the clam shells fell off and disappeared in about 2 weeks. Because of the superficial damage of herpes, no scars were left after the healing, even if the local remains There is temporary pigmentation, which can gradually subside. The varicella rash occurs in batches. In the process of the gradual evolution of the previous rash damage, a new batch of herpes appears again, leading to erythema, papules, herpes and scars. Stage damage can coexist in the same patient at the same time, especially on the 2nd to 3rd day of rash, the rash is often seen in the same part, which is another important feature of varicella rash, with the immunity of the patient Gradually increased, the rash gradually decreased, and the last rash that appeared in the rash period stopped developing and disappeared, and the patient recovered.
3. Clinical classification of chickenpox
According to the clinical characteristics of patients, chickenpox can be divided into the following types:
(1) Ordinary type: the majority of patients with varicella, the prognosis is good, in general, the systemic symptoms of varicella patients are relatively mild, the course of the disease lasts about 1 week, can be self-healing, adult and infant patients often have more rashes The condition is also severe, and the course of the disease can be delayed for several weeks.
(2) Progressive disseminated varicella: can be seen in a variety of reasons leading to weakened resistance, for example, suffering from leukemia, lymphoma and other malignant tumors, or long-term application of various immunosuppressive agents, adrenocortical hormone patients, such patients It is easy to develop into progressive disseminated varicella after infection, and the condition is serious; the viremia lasts for a long time, there are symptoms of high fever and systemic poisoning, the body rash is dense and dense, and new rash appears constantly, herpes is large, Can be fused to form a bullous, or hemorrhagic herpes is not easy to scar, even a large piece of necrosis of the skin and subcutaneous tissue of the rash, sometimes visible spots and ecchymoses on normal skin, the death of patients with progressive disseminated varicella The rate is about 7%.
(3) Primary varicella pneumonia: Most patients with sputum are adults. Primary varicella pneumonia occurs from the first disease day to the sixth disease day, but the severity of the disease is different. May have high fever, cough, chest pain, hemoptysis, difficulty breathing and cyanosis, chest signs are not obvious, or a small amount of dry, wet voice and wheezing; X-ray chest radiograph can be seen diffuse nodular shadows of the lungs, hilar and lung The bottom is more obvious, the pathological process of varicella pneumonia is generally synchronous with the rash, often with the rash subsided and improved; but after a few patients with severe varicella pneumonia disappeared, X-ray shadows can still exist for 2 to 3 months before dissipating.
(4) Varicella encephalopathy (varicella encephalopathy): less common, the clinical manifestations of encephalitis occurred 3 to 8 days after the rash, and a few are seen from 2 weeks before the rash to 3 weeks after the rash, usually 5 ~ 7 years old children, more men than women, clinical features and cerebrospinal fluid examination characteristics similar to other viral encephalitis, the onset of urgency, early no fever and meningeal irritation, common headache, vomiting and paresthesia, or accompanied by Ataxia, nystagmus, dizziness and language disorders, etc.; severe cases may have convulsions, paralysis, lethargy or coma, after the illness may have mental dysfunction, mental retardation and seizures and other sequelae, varicella encephalitis duration of 1 to 3 Week, the case fatality rate is 5% to 25%. Anyone who suffers from coma and convulsions has a serious prognosis.
(5) Others: Patients with severe varicella infection can cause focal necrosis of liver tissue. There are typical intranuclear inclusions in hepatocytes and bile duct epithelial cells. The clinical manifestations are varicella hepatitis. The patient has hepatic enlargement and abnormal liver function. There are reports of jaundice, chickenpox complicated with nephritis, interstitial myocarditis, etc. Serious arrhythmia can cause death to the patient. In addition, infection of chickenpox in early pregnancy may cause fetal malformation; infection of chickenpox in late pregnancy may cause fetal congenital varicella synthesis Sign.
Examine
Chickenpox inspection
The following laboratory tests can be selected if necessary:
1 Take the fresh herpes liquid for electron microscopy, visible herpes virus particles, can quickly identify with variola virus.
2 Within 3 days of onset, the human amniotic membrane was inoculated with liquid in herpes, and the positive rate of virus isolation was higher.
3 Serological examination, commonly used for complement fixation test, varicella patients appear in the serum 1 to 4 days after the emergence of serum-binding antibodies, peaked 2 to 6 weeks, gradually decreased after 6 to 12 months, can also use indirect fluorescent antibodies Method detection,
4PCR method to detect VZV DNA in nasopharyngeal secretions as a sensitive and rapid early diagnosis.
Diagnosis
Varicella diagnosis
diagnosis
Typical chickenpox has the following characteristics:
1 patients are mostly infants and young children, systemic rash appears in batches within 1 to 2 days after fever, and its distribution is centripetal;
2 The rash is experienced by rash, papules, herpes, followed by dry and crusted in 1 to 2 days. Different forms of rash at each stage can coexist in the same part of the patient's body at the same time;
3 typical herpes is oval, thin and easy to break, no umbilical concavity in the central part of herpes; as long as there is no secondary infection, herpes does not purulent, and no scar remains after the infection;
4 In addition to visceral varicella and progressive disseminated varicella patients, the systemic symptoms are generally not heavy;
5 epidemiological history can be consulted with similar patients in the contact population, varicella encephalitis occurs in the course of the rash or after the course of the disease, the diagnosis is not difficult, if the clinical manifestations of encephalitis are seen before the rash, due to its clinical The characteristics and characteristics of cerebrospinal fluid examination are similar to those of other viral encephalitis, so the diagnosis is very difficult; clinically, only after seeing typical herpes, the diagnosis of varicella encephalitis can be made.
Differential diagnosis
(A) impetigo occurs in the area around the nasolabial or extremities, as herpes, followed by pustules, and then scarring, no batch appearance, not seen in the mucosa, no systemic symptoms.
(2) Papular-like urticaria is a fusiform red papule, such as the size of peanuts, with a tip or miliary size of herpes or blisters in the center. It is hard and itchy, distributed in the limbs or torso, not involving the head. Or oral, not scarred.
(3) Herpes zoster herpes is distributed along a certain nerve trunk path, asymmetry, no more than the midline of the trunk, and there is significant burning pain in the local area.
(4) Severe varicella is similar to light smallpox.
(5) Other viruses infected with herpes simplex virus can also cause varicella-like skin lesions. This type of disseminated herpes simplex virus infection is often secondary to skin diseases such as atopic dermatitis or eczema. The diagnosis depends on the results of virus isolation. It is found that enteroviruses, especially Coxsackievirus A, can cause a wide range of varicella-like rashes, usually occurring in the late summer and early autumn when the enterovirus is high, often accompanied by pharyngeal, palm and foot skin lesions. A little help in the identification of chickenpox and enterovirus infection.
