Psoriasis（銀屑?。?/p>

DefinitionClinically,itisachronicnon-infectiousdermatitischaracterizedbyredscalyplaquesthatattackrepeatedly.DefinitionPathogenically,psoriasisisachronicdisorderwithpolygenicpredispositioncombinedwithtriggeringenvironmentalfactorssuchastrauma,infectionormedication.DefinitionHistorically,psoriasisisabenignandoverproliferationofkeratinocytesduetoimbalancedTcellfunction.EpidemiologyPrevalenceinChina:0.123%(1984)

0.47%

(2008,6cities)Morecommoninyouth&middleagedpeopleMale>FemaleCity>countrysideNorth>SouthWhiterace>yellowrace>blackraceAetiologyandPathogenesis

Geneticfactors:polygenicdiseaserelatedHLA---A1,B13,B17,Cw6,etcEnvironmentalfactors:infection,

trauma(bothmentallyandphysically),drugImmunefactors:abnormalactivationofTcellswithcytokinesreleasing(IL-1,IL-6,IL-8,TNF-a)

Histopathology

Epidermis:hyperkeratosis,parakeratosiswithMunro’smicroabscesses,disappearanceofstratumgranulosum,acanthosis.

Dermis:elongationandtwistofdermispapillae,dilatationofcapillaries,inflammatoryinfiltrationNormalskinpsoriasisMunro’smicroabscessClinicalManifestations

Classification:

psoriasisvulgarispsoriasisarthropathicapsoriasiserythrodermicpsoriasispustulosa—localized&generalized

psoriasisvulgarisPrimarylesions:redpapulesormaculopapulesTypicallesions:redscalingplaquesFeatures:wax-likescalesTransparentfilmAuspitzsignCommoninvolvedplaces:scalp,elbow,knee,sacrococcgealskinSpecialinvolvedplaces:nail,glansLesionpatterns:psoriasisguttatapsoriasisnummularispsoriasisannulatapsoriasisrupiodesStages:progressive-static-recedingCourse:chronicallyrepeatedwithalleviationinsummerSubjectivesensation:absentoritchy

AuspitzsignPsoriasisguttataPsoriasisnummularisPsoriasisannulataPsoriasisrupioidesPsoriasishypertrophicaPsoriasiszosteriformisPsoriasisgeographicaKobner’sphenomenaPsoriasisarthropathica

psoriasis+seronegativearthritisarthrocele,arthralgiaankylosisjointmalformationcommoninvolvedjoints:finger&toejointsvertebraljointselbow&kneejointsX-rayofpsoriasisarthropathicaOsteoporosisStenosisofjointcavityErosionofthejointPsoriasispustulosalocalizedgeneralizedLocalizedpsoriasispustulosa

GeneralizedpsoriasispustulosaPsoriasiserythrodermic

generalizededematousrashwithheavyscale,usuallyaccompaniedbyfever,LNenlargementandhypo-proteinemianormalskinislandsinpsoriasiserythrodermicDiagnosisClinicalmanifestations,lesionfeatures,involvedpositionsandpathologyexaminationTreatment

Topicaltreatment

keratoplasticsandkeratolytics:coaltar,anthralinetalcytotoxicdrugs:nitrogenmustard,5-FuetalCorticosteriods:flucinolone,triamcinolone,chlorbetasoleetal

DerivativesofVitD3:calcipotriol

Retinoidacid:Tazarotene

Systemictreatment1.Retinoids:etretinate(Tigason),acitretin(newTigason)---thefirst-linedrugsMainpharmacologicalmechanisms:inhibitabnormalproliferationanddifferentiationofkeratinocytes;keratolysisMainindications:psoriasispustulosa;psoriasiserythrodermic;chronicobstinatepsoriasisvulgarisMainside-effects:monstrosity;drynessofskinandmucosa;abnormalityofhepaticfunctionandhyperlipemia

2.Cytotoxicdrugsorimmunosuppresivedrugs:methotrexate(MTX),cyclosporin-a3.Corticosteroids:onlyusedinpsoriasiserythrodermic,generalizedpsoriasispustulosaandacutepsoriasisarthropathica4.Biologicpreparations

anti-TNF-a:Etanercept,Infliximab,Adalimumab

anti-IL-12,23:Ustekinumab5.Others:antibiotics,vitamins,traditionalChinesemedicinesPhototherapy

NB-UVB:311nmUVA:320-400nmMainmechanisms:inhibitionofproliferationofkeratinocytes;vasodilationMainside-effects:shortterm:phototoxicreactionlongterm:skinaging;skincancerPityriasisRoseaAnacute,self-limitedskineruptionTypicallymanifestsasovalscalylight-redplaqueslocatedalongthelinesofskincleavageontrunkmayberelatedwithinfectionofHHV-7or6ClinicalmanifestationsofpityriasisroseaOvalscalylight-redplaquesBeginsasasingleplaqueontrunk(heraldpatch),whichisfollowedbynumeroussmallerlesions,locatingalongthelinesofskincleavageCommonlyinvolvedplaces:trunk,neckandproximalendsofextremities(centrality)Subjectivesensation:slightitchyCourse:self-limited,usuallylasts6-8weeksPityriasisrosea:ovalscalylight-red