1、Varicella(chickenpox)is the primary infection caused by varicella-zoster virus(VZV).lAfter varicella,the virus establishes latent infection in dorsal root ganglia and its reactivation causes herpes zoster(shingles).lVaricella is characterized by the appearance on the skin and mucous membranes of suc
2、cessive crops of typical vesicles,generally accompanied by a mild constitutional reaction.Varicella-zoster virus(VZV)l Classification:double-stranded DNA virus Family:Herpesviridae Subfamily:Alpha herpesvirinael Serotype:Only onel Locations:Patients respiratory secretions,blood,vesicle fluidlResista
3、nce:Sensitive to heat,acid and disinfectant l Infectious sources PatientsThe infective stage is from about 24 hr before the appearance of the rash to all lesions are crusted l Routes of transmissionRespiratory transmission:spread by droplet Direct contact Mother-to-fetus transmission：congenital vari
4、cellal Population susceptibility 90%of reported patients are under 10-yr of age.The peak age of incidence is 2-6 yr.l Peak seasons:winter and spring regional lymph nodes viremia viremia,skin,MaculopapuleVesiclesCloudy vesiclesCrustAngiotelectasis in dermisBallooning degeneration in celllayerApocytes
5、 invade in fluid fluid absorbedOther organsThe severity of the disease varies from a few lesions with little evidence of systemic illness to many hundreds of lesions and extreme toxicity the incubation period varies from 10-21 days,but the average is 13-17 days.there may be slight fever,malaise,or a
6、norexia.Exanthem stage:1)Rash rash development process:maculopapule-“tear-drop”vesicles-cloudy vesicles-crusts rash characteristics:lappear in batches(development of several crops of rash)lfour kinds of rash at the same timelconcentric distributionlmucosa involvement rash sequence:trunk-face and sca
7、lp-extremities rash pruritus gogoExanthem stage:1)Rash rash development process:maculopapule-“tear-drop”vesicles-cloudy vesicles-crusts rash characteristics:lappear in batches(development of several crops of rash)lfour kinds of rash at the same timelconcentric distributionlmucosa involvement rash se
8、quence:trunk-face and scalp-extremities rash pruritus concentric distributionExanthem stage:1)Rash rash development process:maculopapule-“tear-drop”vesicles-cloudy vesicles-crusts rash characteristics:lappear in batches(development of several crops of rash)lfour kinds of rash at the same timelconcen
9、tric distributionlmucosa involvement rash sequence:trunk-face and scalp-extremities rash pruritus mucosa involvementExanthem stage:1)Rash rash development process:maculopapule-“tear-drop”vesicles-cloudy vesicles-crusts rash characteristics:lappear in batches(development of several crops of rash)lfou
10、r kinds of rash at the same timelconcentric distributionlmucosa involvement rash sequence:trunk-face and scalp-extremities rash pruritus extreme toxic symptoms with temperatures ranging from 39+-40+severe rashthrombocytopeniamore complicationshigh mortalityextreme toxic symptoms with temperatures ra
11、nging from 39+-40+severe rashthrombocytopeniamore complicationshigh mortalitycongenital varicella congenital varicella syndrome the skin lesions is the most common complication.Such as impetigo（脓疱）,erysipelas（丹毒）,cellulitis（蜂窝组织炎）、surgical scarflet fever Varicella encephalitis the most common centra
12、l nervous system complication.Cerebellar signs has a much better prognosis than cerebral symptoms of convulsions and coma.Overall mortality rates vary from 5-25%.About 15%of survivors have permanent sequelae of seizures,mental retardation,or behavior disturbances.Guillain-Barre syndrome（吉兰-巴雷综合征）Rey
13、e syndrome（瑞氏综合征）（瑞氏综合征）Transverse myelitis（横贯性脊髓炎）Facial palsyOptic neuritis,ect.uncommon in children20-30%of adults with chickenpox have clinical or roentgenographic signs of lung involvement.Recovery is usually prompt,but roentgenographic changes may persist for 6-12 wk in the more seriously ill.
14、Fatalities have been reported.MyocarditisLeukocytopeniaNephritis,ect.l Blood routine:a mild leukocytopenia l Multinucleated giant cells:it can be demonstrated in scrapings from the floors of fresh vesicles.l Virus isolation:virus can be isolated in human tissue culture cell lines.l serological study
15、 Epidemiologic dataAgeSeasonsHistory of contact with patientHistory of inoculationClinical data:Typical rash The diagnosis is usually made from the characteristic clinical picture,and laboratory confirmation is rarely needed.Differential diagnosis Hand-foot-and-mouth diseaseUrticaria papulosahand-fo
16、ot-and-mouth diseasehand-foot-and-mouth diseasehand-foot-and-mouth diseaseUrticaria papulosaUrticaria papulosaTreatmentSymptomatic treatment:abatement of fever antipruritic agentssedationWear mittens and keeping nails shortDaily changes of clothesAntiviral therapy:Acyclovir（阿昔洛韦）（阿昔洛韦）Interferon-Com
17、plication treatment:antibiotic therapy if there is a superinfection with bacteriaCortical hormone is forbiddedSalicylic acid（水杨酸）（水杨酸）agent is not be used as possible Control of sources of infections Abrupt the ways of transmission Protect the susceptible passive immunization active immunization1)Co
18、ntrol of sources of infectionsThe patient will be isolated until all lesions are crustedThe susceptible contacts will be isolated for clinical observation for 3 weeks after exposure.Quarantine period 2)Abrupt the ways of transmission3)Protect the susceptible passive immunization zoster immune globulin(ZIG).given within 72 hr of exposure.125-625U/kg active immunization Varicella Attenuated Live Vaccine Efficacy:85%-95%,more than ten yearsThe prognosis is usually goodFatalities occur from the complicationsThanks
