Chicken pox – the acute infectious disease of a virus etiology which is characterized by developing of characteristic vesiculate rash in a background of the general intoksikatsionny syndrome. The causative agent of chicken pox - the herpes virus 3 types which is transmitted from the patient with an airborne way. Chicken pox belongs to the most widespread children's infections. It is shown by the characteristic plentiful itching vesiculate rashes developing at height of fever and all-infectious manifestations. The typical clinic allows to diagnose a disease, without conducting any additional researches. Treatment of chicken pox generally symptomatic. For prevention of secondary infection antiseptic processing of elements of rash is recommended.
Chicken pox – the acute infectious disease of a virus etiology which is characterized by developing of characteristic vesiculate rash in a background of the general intoksikatsionny syndrome.
Characteristic of the activator
Chicken pox is caused by the Varicella Zoster virus of family of gerpesvirus, it is a virus of herpes of the person 3 types. It is the DNA-containing virus a little steady in the external environment, capable to replication only in a human body. The inactivation of a virus occurs quickly enough at impact of a sunlight, ultra-violet radiation, when heating, drying. The tank and a source of chicken pox are sick people within 10 last days of the incubatory period and the fifth or seventh days of the period of a rash.
Chicken pox is transmitted on the aerosol mechanism in the airborne way. In view of weak stability of a virus contact and household transfer is poor-selling. Spread of a virus with the fine aerosol allocated by patients at cough, sneezing, a conversation is possible on rather long distance within the room, the drift with air current to adjacent rooms is probable. There is a probability of transmission of infection transplatsentarno.
People possess a high susceptibility to an infection, after transferring of chicken pox intense lifelong immunity remains. Children of the first months of life are protected from an infection by the antibodies received from mother. Chicken pox the children of preschool and younger school age visiting organized children's collectives most often have. About 70-90% of the population have chicken pox aged up to 15 years. Incidence in the cities is more than twice higher, than in rural settlements. The peak of incidence of chicken pox falls on the autumn and winter period.
Pathogenesis of chicken pox
Entrance gate of an infection is the mucous membrane of airways. The virus takes root and collects in epithelium cages, extending in the subsequent in regionarny lymph nodes and further in the general blood-groove. Circulation of a virus with current of blood causes the phenomena of the general intoxication. The virus of chicken pox has affinity to an epithelium of integumentary fabrics. Replication of a virus in an epitelialny cage promotes her death, on the place of the died-off cages there are cavities which are filled with exudate (inflammatory liquid) – the vesicle is formed. After opening of vesicles there are crusts. After office of a crust under it again created epidermis is found. Rashes at chicken pox can be formed both on skin, and on mucous membranes where quickly enough vesicles progress in an erosion.
Chicken pox at persons with the weakened immune system proceeds in a severe form, promotes development of complications, secondary infection, an exacerbation of chronic diseases. At pregnancy the probability of transfer of chicken pox from mother to a fruit makes 0,4% in the first 14 weeks and increases to 1% up to the 20th week then the risk of infection of a fruit is practically absent. As an effective preventive measure to the pregnant women having chicken pox appoint the specific immunoglobulins helping to reduce probability of transmission of infection to the child to a minimum. The chicken pox which developed one week prior to childbirth and in the subsequent after the delivery month is more dangerous.
Resistant lifelong immunity reliably protects an organism from a repeated infection, however at significant decrease in immune properties of an organism the adults who had chicken pox in the childhood can catch it again. The phenomenon of a latent carriage of the virus of chicken pox collecting in cells of nerve ganglions and capable to become more active takes place, causing shingles. Mechanisms of virus activation at such carriage are still insufficiently clear.
Symptoms of chicken pox
The incubatory period of chicken pox fluctuates within 1-3 weeks. At children the prodromalny phenomena are poorly expressed, or are not observed at all, in general - a current easy with insignificant deterioration in the general state. Adults are inclined to heavier course of chicken pox with the expressed intoxication symptomatology (a fever, a headache, an ache in a body), fever, sometimes notes nausea, vomiting. Rashes at children can unexpectedly arise against the background of lack of any general symptomatology. At adults the period of rashes quite often begins later, fever at emergence of elements of rash can remain some time.
Rash at chicken pox has character of bullous dermatitis. Rashes represent the single elements arising on any parts of the body and extending without any regularity. Rash elements originally represent the red specks progressing in papules and then - in the small equal single-chamber vesicles with transparent liquid which are falling down when piercing. The opened vesicles form crusts. Simultaneous existence of elements at different stages of development and emergence new is characteristic of chicken pox (podsypaniye).
Rash at chicken pox causes an intensive itch, when combing infection of vesicles with formation is possible. Pustula when mending can leave behind a hem (pockmark). Not infected vesicles of hems do not leave, after office of crusts the healthy new epithelium is found. At suppuration of sypny elements the general states usually worsens, intoxication is aggravated. Rash at adults is usually more plentiful, and in most cases pustula are formed of vesicles.
Rash extends practically on all surface of a body except for palms and soles, mainly in the field of a hairy part of the head, on a face, a neck. Podsypaniya (emergence of new elements) it is possible for 3-8 days (at adults, as a rule, they are followed by new feverish waves). Intoxication falls down along with the termination of podsypaniye. Rash can develop on mucous membranes of a mouth, genitals, sometimes - on a conjunctiva. Sypny elements on mucous progress in erosion and ulcers. At adults rash can be followed by a limfoadenopatiya, damage of lymph nodes is not characteristic of children.
Besides a typical current, distinguish the erased form of chicken pox proceeding without symptoms of intoxication and with short-term rare rash and also the severe forms differing on bullous, hemorrhagic and gangrenous. The bullous form is characterized by rash in the form of the large flabby bubbles leaving long beginning to live ulcer defects after opening. Such form is characteristic of people with a serious chronic illness. The hemorrhagic form is followed by hemorrhagic diathesis, on skin and mucous membranes small hemorrhages are noted, there can be bleedings from a nose. Vesicles have a brownish shade at the expense of hemorrhagic contents. At persons with much the weakened organism chicken pox can proceed in a gangrenous form: quickly growing vesicles with hemorrhagic contents are opened with formation of the necrotic black crusts surrounded with a rim of the inflamed skin.
Complications of chicken pox
In most cases the course of chicken pox good-quality, complications are noted no more than at 5% of patients. Among them the diseases caused by a secondary infection prevail: abscesses, phlegmons, in hard cases – sepsis. The dangerous, difficult giving in to therapy complication is viral (vetryanochny) pneumonia. In certain cases chicken pox can provoke keratit, encephalitis, myocarditis, nephrite, arthritises, hepatitis. Severe forms of diseases at adults are inclined to complications, in particular at the accompanying chronic pathologies and the weakened immune system. At children of a complication are noted in exceptional cases.
Diagnosis of chicken pox
Diagnosis of chicken pox in clinical practice is made on the basis of a characteristic clinical picture. The general blood test at chicken pox is not specific, pathological changes can be limited to acceleration of SOE, or signal about an inflammatory disease with the intensity proportional to the general intoksikatsionny symptomatology.
The virologic research means identification of vireos at electromicroscopy of the vesicular liquid painted by silvering. Serological diagnostics has retrospective value and is made by means of RSK, RTGA in pair serums.
Treatment of chicken pox
Chicken pox treat on an outpatient basis, except for cases of a heavy current with intensive obshcheintoksikatsionny manifestations. Etiotropny therapy is not developed, in case of formation resort to antibiotic treatment by a short course in average dosages. Persons with immune insufficiency can appoint antiviral medicines: acyclovir, , interferon alpha (interferon of new generation). Early purpose of interferon promotes easier and short-term course of an infection, and also reduces risk of development of complications.
Therapy of chicken pox includes measures for care of skin for the purpose of the prevention of purulent complications: vesicles are greased with antiseptic solutions: 1% solution diamond green, concentrated – potassium permanganate ("brilliant green", "potassium permanganate"). Ulcerations of mucous are processed by hydrogen peroxide in 3% cultivation or an etakridina a lactate. The intensive itch in the field of rashes is facilitated, greasing sites of skin with glycerin or rubbing off the divorced vinegar, alcohol. As pathogenetic means appoint antihistaminic medicines. To pregnant women and patients with a severe form appoint specific protivovetryanochny immunoglobulin.
Forecast and prevention of chicken pox
The forecast is favorable, the disease comes to an end with recovery. Vesicles pass into nothingness, pustula can leave ospenny hems. Considerable deterioration in the forecast at persons with an immunodeficiency, a serious system illness.
Prevention of chicken pox consists in the prevention of a drift of an infection in organized children's collectives what at identification of cases quarantine actions are made for. Patients are isolated for 9 days from the moment of emergence of rashes contacting to patients children separated for 21 days. In case day of contact with the patient is precisely defined, the child is not allowed in children's collective from 11 to 21 days after contact. To the contact children who did not have earlier chicken pox with the weakened immunity as a preventive measure appoint protivovetryanochny immunoglobulin.
Lately vaccination against chicken pox began to be applied. Vaccines of Varilriks (Belgium) and Okavaks (Japan) are for this purpose used.