The chicken pox is a infantile Maladie eruptive frequent, characterized by its very large Contagiosité. It translates the primary infection by the Virus chicken pox-shingles or VZV, virus of the family Herpesviridae . In more than 90% of the cases it occurs in the child between 1 and 15 years. Its period of Incubation is 14 days on average (from 10 to 21 days).
Benign in the quite bearing child, it can be frightening at the adult not immunized, the immunodéprimé, the expectant mother and the Nouveau-né.
See also: Virus chicken pox-shingles
The virus of the chicken pox-shingles, as its name indicates it, is in the beginning chicken pox and Zona. It belongs to the group of the Herpesviridae. The first infestation involves the table of chicken pox then the virus takes refuge in the nerve-knots sensitive where there can remain latent lasting of the decades. Its secondary reactivation is responsible for the shingles.
The virus is present in the Nez and the throat before the eruption and in the blister S at the time of the latter. Contagiousness begins between one and two days before the eruption. It finishes during the complete cure (loss of all the crusts resulting from the cicatrization of the blisters). It can be prolonged in the serious forms.
The virus would penetrate in the organization through the respiratory tracts, joining the lymphatic ganglia to multiply there, then would be disseminated after the incubation period, in the throat and the skin.
EpidemiologyIn the moderated countries, more than 90% of the adults had chicken pox during childhood or adolescence (generally between 1 and 9 years). The disease is declared often later in the tropical countries.
The incidence is higher in winter and in spring. The monitoring of the evolution of the incidence in France is carried out by the Réseau Sentinels of the Inserm.
The latest forms are appreciably more serious.
The infantile disease
Symptom S currents
Malayan general and Fever relatively low a few hours before the cutaneous eruption.
- Cutaneous eruption:
- small Macule S dew appears initially. They quickly will overlap with Vésicule S in dewdrops, which in the three days will desiccate and form a crust. There can remain transitory lesions hypopigmentés, or scars.
- These lesions generally appear in first on the scalp, then on the Thorax and the mucous membranes, then on the members, with respect of the palmo-plantar areas, and finally with the face.
- the various series of lesions shifted in time make that the various types of lesions coexist on all the body.
- the importance of the eruption is very variable from one individual to another.
- Difficulty of feeding because of the blisters which are formed sometimes in the Bouche.
- Strong itchings (Prurit).
- important Cough in certain cases.
It is generally obvious in front of the aspect of the eruption and the concept of a contact in the two weeks which precede with another patient.
On a purely exceptional basis, the diagnosis can be confirmed by the research of the virus in the blisters.
The search for Anticorps against chicken pox (Serology) can be made but there exist some reactions crossed with the antibodies directed against the others Herpèsvirus. This research can be useful in order to target the people to be vaccinated (absence of antibody).
Cure in 7 to 16 days for adults and children.
- Généralement the Immunité is final but it is possible, though extremely rare, to observe second chicken pox at a immunodéprimé subject.
- the Virus remains in sleep and can be later at the origin of a Zona.
Complicated chicken pox
Although benign in the very large majority of the cases, chicken pox can become complicated, in particular in the immunodéprimés subjects, the infants, the adults, the expectant mothers.
Impétigo : bacterial superinfection in the event of scraping of the cutaneous lesions
- varicelleuse Pneumopathy: it is not rare in the adult, and appears by aspecific acute pulmonary Symptôme S (Toux, Fièvre raised, difficulties of breathing, Hémoptysie).
- acute Ataxia cérébelleuse: sees itself in the child, of benign evolution (a case on 4000).
- Syndrome of Reye: it is a Encéphalite extremely serious, exceptional, due to the catch of Anti-inflammatoire S, such as the Aspirine.
TreatmentAt the banal forms of childhood, the disease is not serious and raises only of one treatment of the symptoms: fever, itchings.
At the time of the eruptive phase:
To prevent that the child scrapes himself (to cut the nails to the short-nap cloth, even use of pulley blocks in the small child), because that can cause final Cicatrice S cutaneous unaesthetic. One can also give to the child a bath tepid water in which one will have made dissolve a little Bicarbonate of soda in order to calm itchings. A Antihistaminique can possibly be prescribed by your doctor.
- To isolate the child from his comrades and the adults not having been infected at the time of their childhood. The school ousting is probable and decides on a case-by-case basis. The contagion starting most of the time before the symptoms were not identified, it is generally too late to completely stop the transmission of the disease.
- To consult a Doctor, it will prescribe Antiseptique S and sometimes of the Antibiotique S, only in the event of superinfection (impetiginisation).
- To give to drinking in abundance.
- not to give an Acetylsalicylic acid Anti-inflammatoire S containing of the , standard Aspirine , anti-inflammatory drug nor stéroïdien (corticoids, as well in local application as by way oral - what arrives in the children suffering from severe eczema), or not stéroïdien (in particular of Ibuprofène type), which is formally contra-indicated because of the risk - extremely rare of Syndrome of Reye
- not to use creams, gel, talc, pomades, which increase the risk of superinfection by maceration.
In the serious forms, an antiviral treatment is prescribed: The Aciclovir is regularly effective, with exceptional resistances.
VaccinationIt is done in a single injection in the child of less than 12 years, and in two injections spaced of one to two months, in the older child. It can be made in an isolated way, or grouped (vaccination anti-chicken pox, Rubéole, Oreillons and Rougeole).
The effectiveness reaches nearly 90%, and in the event of chicken pox, the latter is appreciably less serious. Moreover, it should theoretically decrease the risk of shingles but that was not shown formally. The effectiveness of vaccination however appreciably seems to decrease with time.
Vaccination remains sure with less than 3 accidents for 100.000 amounts, the latter occurring primarily in the immunodéprimé child.
In FranceSince September 2004 the Vaccin is available in France. It is not obligatory for the children because of the benignity of the disease and the risk to move the disease towards the adulthood, therefore worms of the forms much more serious. It is recommended (and refunded) in 4 cases:
Vaccination post-exposure in the 3 days following the exposure to a patient with eruption, in the adults immunocompétents without antecedents of chicken pox.
- entered in 1st year of the medical studies and ancillary medical, for the students without antecedents of chicken pox and whose Sérologie is negative.
- any person without antecedents of chicken pox and whose Sérologie is negative, in close contact with immunodéprimées people .
- children without antecedents of chicken pox and whose Sérologie is negative, candidates receivers with a Clerc's Office of solid body, in the six months preceding the intervention.
The indications for vaccination against chicken pox are the following ones:
- Young people from 11 to 15 years not having a anamnèse of chicken pox.
- Prone as of the 12 months age not immunes (IgG negative) presenting following risks of complication:
- Leukemia; cancer; before an immunosuppressive therapy or a transplantation; child infected by the HIV, before immunodéficience.
- suffering Children of a serious eczema.
- People in close contact with the above-mentioned patients (parents, phratry).
- Medical personnel and looking after.
- vaccine Correction in the adults of less 40ans not having a anamnèse of chicken pox.
Other countriesIn other countries, vaccination is much more systematic (the United States, Canada, Taiwan…), involving a strong reduction in the disease and serious forms of this one as well as a considerable reduction in term of cost (drugs, absenteeism, guard of child…).
Other preventive medicationsIn certain cases, the injection of Immunoglobuline S specific can prevent the appearance of the disease or reduce gravity of it. They are primarily used in the event of counter-indication with vaccination (immunodépression).
To aciclovir also a certain effectiveness showed when it is given early after the contage (contamination).
Chicken pox and Pregnancy
At the Expectant mother this disease is serious for the woman and the Fœtus:
- In the expectant mother, chicken pox is responsible for Pneumonie mortal in 10% of the cases
- At the fetus, chicken pox can cause Malformation S if the disease is contracted before five months
- At the newborn, congenital chicken pox néonatale can occur if his/her mother had chicken pox a few days before or after the birth. This congenital chicken pox néonatale is very serious with a mortality of 20%.
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