病毒性細(xì)菌性皮膚病 Viral Dermatoses

病毒性細(xì)菌性皮膚病ViralDermatosesGeneralDescriptionDefinitionViraldermatosesarethecutaneousdiseasesresultingfromviralinfections.ClassificationofViraldermatosesHerpesvirusgroupHerpessimplesxVaricella(Chickenpox)HerpesZosterRosealaInfantum(Sixthdisease)Kaposi’ssarcomaClassificationofViraldermatosesPoxvirusgroup

Molluscumcontagiosum,milker’snodulesPapovavirusgroup

Warts(commonwarts,Flatwarts,plantarwarts,genitalwarts)ClassificationofViraldermatosesParvovirus

Erythemainfectiosum(fifthdisease)(B19virus)Paramyxovirusgroup

Measles,rubellaClassificationofViraldermatosesPicornavirusgroup(enteroviruses)Hand-fooot–mouthdisease(coxackievirus)RetrovirusesAIDSHerpesSimplexEtiologyHerpesSimplexVirus(HSV):DNAVirusTwoantigenictypes:HSV-1,HSV-2

HSV-1:lesionsonthelips,faceHSV-2:genitalherpesLesionsanywheremaybecausedbyeitherantigenictype.Transmission:Intimatecontact(directinoculationthroughtraumatizedskin)PrimaryinfectionandrecurrentinfectionPrimaryinfection:firstinfection

Afterprimaryinfectionvirusmigratestotheneuronalcellsinganglionlatentinfectionlatentvirustoreactivatebytriggeringfactorsvirusparticlesmoveonthenervereplicateintheepithelialcells

recurrentinfectionTriggeringfactors:fever,trauma,emotionalstress,menstruationEpidemiology85%ofadultsworldwideareseropositireforHSV-1.SeroprevalenceforHSV-2islower,appearattheageofonsetofsexualactivity.

USA:~23%ofadultsareinfectedwithHSV-2Developingcountries:60~95%ofinfectionratesofHSV-2Incubativeorsubclinicalinfection:90%ofallinfected

ClinialmanifestationFeaturesofthelesion:multiplesmallpapules,vesicles,clustedtogether.Maturelesion:groupedvesiclesand/orpustulesonanerythematousedematousbaseCommonsiteforlesions:face,lips,mouth,neck,anogenitalareaHealwithin1-2weeksDiagnosis

ClinicalDiagnosisLaboratoryTestTzancksmear:takeasmearofcellsfromthebaseoftheskinlesionspreadthecellsonaglassslidestainwithwrightorGiemsaStainlookformultinucleatedgiantcellsNonspecific:HSVVZVAccuracyrate:60~90%Falsepositiverate:3~12%DetectionofvirusantigenofthelesionMaterials:vesicularfluid,cellsfromthebaseofskinlesionMethods:directfluorescentantibodytest

immunoperoxidasetchniquesViruscultureEmphasis

Serologictests(detectionofanti-HSVantibodyoftheblood)aregenerallynotusedindeterminingwhetheraskinlesionisduetoHSVinfection.Apositiveresulttoaserologictestindicatesonlythattheindividualisinfectedwiththatvirus,notthattheviralinfectionisthecauseofthecurrentlesion.ThreatmentTherapeuticprincipleToshortendiseasedurationTopreventbacterialinfectionTopreventrecurrenceThreatmentAnti-HSVtherapyPrimaryinfection:Acyclovir:0.2g,fivetimes/day×7-10daysValaciclovir:0.3g,bid×7-10daysFamcyclovir:0.25g,tid×7-10daysRecurrentinfection:treatmentduration5daysThreatmentSevererecurrentcases

acyclovir04gbidvalacyclovir0.3gqidfamcyclovir0.25gbid4Mto1YThreatmentOtherantiviralagentslikeIFN-ormaybeapplied

Topicaltherapy

1%pencyclonircream,1%acyclovircream,topicalantibioticsVaricella&herpes

zosterEtiologyVaricela-zostervirus(VZV):humanherpesvirus-type3Tranmmission:directcontactrespiratoryrouteAverycommunicablediseasePrimaryinfection:varicellaorsubclinicalinfectionVirusreactivation:herpeszosterCellularimmunityandherpeszoster90%casesofvaricela＜10yearsofageClinicalmanifestationVaricellaSkinlesion:macules→vesicles(within24hs)→successivefreshvesicles(within4days)Hemorrhagic,necroticorbullouslesionThesiteoflesions:trunck,face,oralmucosaOthersymptoms:fever(moderate)pruritus,secondaryinfectionHerpeszosterFeaturesofthelesions:

OccursunilateralywithinthedistributionofacranialorspinalsensorynerveSkinlesions:papules,plaquesoferythema,blistersinthedermatomePainassociatedwithherpeszosterDiseaseduration:2-3weeksintheyounger,6weeksormoreintheelderlyDiagnosis,differentialdiagnosisHerpeszosterandherpessimplexIntheearlystagesofherpeszoster,ifthenumberoflesionsofzosterislimited,itcanberelativelyindistinguishablefromherpessimplex.Herpeszoster:morepainfull,progresstoinvolvemoreareaover24hsTreatmentVaricellaAntiviraltherapyacyclovir20mg/kg/d×5days,notroutinlyrecommendedTopicalantipruriticlotionsHerpesZosterGeneraltherapyRestrictphysicalactivitiesLocalapplicationsofheatTopicalanesthetics,antipruriticlotion,topicalantiviralagentsVesicularstage:coolcompressAntiviraltherapy:reducethedurationofpainStartpreferablywithinthefirst3or4daysSeverecases:intravenoustherapy(acyclovir,5mg/kg,tid)RefrencedosesAcyclovir0.8g5times/day×7daysValaciclovir1.0gtid×7daysFamciclovir0.5gtid×7daysZosterassociatedpainDrugtherapy:

simpleanalgesicslikeaspirinTricyclicantidepresantslikeamitriptylineanticonvulsantslikecarbamarepineLocalanesthetics:10%lidocaingelorpatchesNerveblocksBacterialDermatoses

ImpetigoEtiology50~70%ofcases:staphylococcusaurensThereminder:streptococcusoracombinationOccurfrequentlyinchildreninhot,humidweatherSourcesofinfectionforchildren:pets,dirtyfingernails,crowdedhousingareasClinicalmanifestationNonbullousimpetigo

Beginswith2-mmerythematousmaculesvesiclesorbullaeseropurulentdischargegoldenyellowcrusts

spreadbyscratchingandautoinoculationBullousimpetigo

occursinnew-borninfants(4th-5thdayoflife)bullaeintheface,handandothersiteslaterweakness,feverorsubnormaltemperatureDiarrheaBacteremia,pneumoniaormeningitisDiagnosisClinicaldiagnosisBacterialexamination:gramstainorcultureTreatmentTopicalagentsRivanol(CompoundEthacridineSolution)2%mupirocinointmentothertopicalantibioticagentsSystemicagentsAntibioticsSemisyntheticpenicillin(penicillinase-resistant)likedicioxacillinCephalosporinErythromycine,azithromycineClindamycineStaphylococcalscaldedskinsyndrome