西医大中西医结合皮肤性病学教案第4讲 药疹、带状疱疹、疥疮

药疹、带状疱疹、疥疮教学目的与要求：目的：认识和掌握药疹的定义、病因病机、诊断和鉴别诊断以及治疗和预防原则。认识和掌握带状疱疹、疥疮的病因、诊断和鉴别诊断以及治疗原则。要求：掌握引起药疹的常见药物种类和临床表现；1.

掌握重症药疹的治疗原则。2.

掌握带状疱疹、疥疮的临床表现和诊断、治疗原则。大体内容与时间安排，教学方法：内容：复习、概括总论的知识要点，比较总论、各论学习方法的异同

5分钟药疹的定义、发病机理、变态反应性药疹的特点

25分钟药疹的临床表现、诊断和鉴别诊断

30分钟药疹的治疗原则和预防

20分钟带状疱疹的病因病机、临床表现和诊断、治疗原则

20分钟疥疮的病因病机、临床表现和诊断、治疗原则

15分钟小结

5分钟方法：运用启发式、讨论式等多种教学方法简要复习、概括总论的知识要点，比较总论、各论学习方法的异同。恰当开展病案式教学及双语教学，以大量图片、简表对比加深感性认识。布置一些内容自学，弥补教学学时减少的不足。教学重点、难点：重点：

药疹的定义、病因病机；药疹、带状疱疹、疥疮的临床表现；药疹、带状疱疹的诊断；变态反应性药疹的特点难点：

药疹的临床表现及鉴别诊断、重症药疹的治疗原则Drugeruption

药疹(drugeruption)亦称\t"/kecheng/2013/_blank"药物性皮炎(dermatitismedicamentosa)，是药物通过内服、注射、吸入、灌肠、栓剂使用，甚至通过破损皮肤等途径进入人体后，在皮肤粘膜上引起的炎症性皮疹，严重者尚可累及机体的其他系统。由药物引起的非治疗性反应，统称为\t"/kecheng/2013/_blank"药物反应，药疹仅是其中的一种表现形式。

发病率Frequency:IntheUS:

Drugeruptionsoccurinapproximately2-5%ofinpatients（住院病人)andinmorethan1%ofoutpatients（门诊病人).Internationally:

Drugeruptionsoccurinapproximately2-3%ofinpatients.死亡率Mortality:Mostdrugeruptionsaremild,self-limitedandusuallyresolveaftertheoffendingagenthasbeendiscontinued.Severeandpotentiallylife-threateningeruptionsoccurinapproximately1in1000hospitalpatients.Mortalityratesforerythemamultiforme(EM)majoraresignificantlyhigher.Stevens-Johnsonsyndrome(SJS)hasamortalityratebelow5%,whereastherateforTENapproaches20-30%;mostpatientsdiefromsepsis.

一、

病因:1.个体因素2.药物因素Allprescription（处方药)andover-the-counter（OTC非处方药)drugsincludingtopicalagents,vitamins,andherbalandhomeopathicremedies临床上易引起药疹的药物有：①

抗生素②

解热镇痛类③

镇静催眠药及抗\t"/kecheng/2013/_blank"癫痫药④

异种血清制剂及疫苗等⑤

中药二、发病机制Pathophysiology:：

1.

免疫性反应immunologicallymediatedreactions2.非免疫性反应两大类。nonimmunologicallymediatedreactions.ImmunologicallymediatedreactionsCoombsandGellproposed4typesofimmunologicallymediatedreactions,asfollows:TypeIisimmunoglobulinE(IgE)–dependentreactions,whichresultinurticaria,angioedema,andanaphylaxis.TypeIIiscytotoxicreactions,whichresultinhemolysisandpurpura.TypeIIIisimmunecomplexreactions,whichresultinvasculitis,serumsickness,andurticaria.TypeIVisdelayed-typereactionswithcell-mediatedhypersensitivity,whichresultincontactdermatitis,exanthematousreactions,andphotoallergicreactions.

变态反应性药疹的特点：只发生于少数过敏体质的服药者皮疹的轻重与药理及毒理作用无关有一定的潜伏期皮疹形态各异交叉过敏及多价过敏现象停止致敏药物，糖皮质激素治疗常有效。

三、临床表现：Althoughmostdrugeruptionsareexanthematous,differenttypes医学.全在线ofdrugeruptionsexist.Witheverydrugeruption,itisimportanttoevaluateforcertainclinicalfeaturesthatmayindicateaseverepotentiallylife-threateningdrugreaction,suchasTENorhypersensitivitysyndrome.Suchfeaturesincludethefollowing:MucousmembraneerosionsBlisters(Blistersheraldaseveredrugeruption.)Nikolskysign(epidermissloughsoffwithlateralpressure)ConfluenterythemaAngioedemaandtongueswellingPalpablepurpuraSkinnecrosisLymphadenopathyHighfever,dyspnea,orhypotension药疹的临床表现多种多样1．

固定型药疹Fixeddrugeruptions2．

\t"/kecheng/2013/_blank"荨麻疹型药疹Urticarial3．

\t"/kecheng/2013/_blank"麻疹样或\t"/kecheng/2013/_blank"猩红热样药疹Morbilliformorexanthematous4．

\t"/kecheng/2013/_blank"湿疹型药疹5．

紫癜型药疹6．

多形红斑型药疹EM-Includesaspectrumofdiseases,eg,EMminorandEMmajor;manycategorizeSJS(10%oftheskin)andTEN(30%ormorethetotalbodysurfacearea)asEMmajoranddifferentiatethembybody-surfaceinvolvement7．

大疱性表皮松解型药疹8．

剥脱性皮炎型药疹Erythroderma四、诊断及鉴别诊断：诊断可依据：①有明确的服药史；②有一定的潜伏期；③除固定型药疹外，皮疹多对称分布，颜色鲜红；④瘙痒明显；⑤排除与皮损相似的其它皮肤病及发疹性传染病。鉴别诊断：①麻疹或猩红热相鉴别②金葡菌性烫伤样皮肤综合征相鉴别。③\t"/kecheng/2013/_blank"生殖器疱疹、硬下疳等鉴别。

五、治疗：原则：①停用一切可疑致敏药物及结构相似药物；②加速致敏药物的排出；③对症治疗已经出现的皮损和症状；④注意药物的交叉过敏或多价过敏。⑤预防药疹的再次发生。

重型药疹

应及时抢救，防止病情加重，减少并发症及后遗症，加强护理，缩短病程，降低死亡率。原则：①及早足量使用糖皮质激素；②预防和治疗感染及并发症；③加强支持疗法；④加强护理及局部治疗。

六、预防：病毒性皮肤病病毒可分为脱氧\t"/kecheng/2013/_blank"核糖核酸（DNA)病毒和核糖核酸（RNA)病毒两大类。根据病毒性皮肤病的不同临床表现特点，可将其分为3型：1．新生物型2．疱疹型3．红斑发疹型Shingles(HerpesZoster)Shingles(otherwiseknownasHerpesZoster)isapainful,blisteringrashcausedbythe

chickenpox

(varicella)virus,whichaffectsonlyalimitedareaofskin,andmakesyoufeelsurprisinglytired,rundown,andevendepressed.\t"/kecheng/2013/_blank"水痘(varicella)和带状疱疹（Herpeszoster)是由同一病毒即水痘-带状疱疹病毒(varicella-zostervirus,

VZV)引起的两种不同的疾病。水痘是一种以散在分布的水疱为特征、传染性很强的疾病，多见于儿童。带状疱疹以群集小水疱沿神经走向单侧分布，伴明显神经痛为特征，多见于成人，中医称为\t"/kecheng/2013/_blank"缠腰火丹。一、病因CausesYoucanonlygetshingles(HerpesZoster)ifyouhavepreviouslyhad

chickenpox.Afterhavingchickenpoxthevirusliesdormantinthenerves,andshinglesoccurswhenitisrevitalisedinoneparticularnervetotheskin,thusexplainingthewayitaffectsaclearlydemarcatedbandofskinonly.Usuallythecauseisadecreaseinyourbody"snaturalresistance,whichmaycomethroughotherinfections,stress,beinggenerallyrundown,oroccasionally,whenthebody"simmunedefencesareaffectedbycertaindrugsorotherimmunedeficiencies.

病原体为水痘-带状疱疹病毒。具嗜神经和皮肤的特性。

三、临床表现1.现全身或局部前驱症状1日～4日后，皮肤出现群集的小水疱或丘疱疹。疱液澄清或血疱，沿神经走向呈带状排列，基底常绕以红晕。一般不超过躯干中线。2.多见于肋间神经或三叉神经第一分支区，亦可见于腰腹部、四肢及耳部等。3.神经痛是本病的特征之一。

四、诊断及鉴别诊断：Thepatternoftherash,intheformofblistersusuallyclinchesthediagnosis,butasampleofthefluidfromtheblisters,orofbloodcanconfirmit.Itisunlikelythatyourdoctorwillneedtodoanytests.带状疱疹根据群集小水疱，沿神经走向，单侧分布，有明显的神经痛，一般诊断不难。应与\t"/kecheng/2013/_blank"单纯疱疹、\t"/kecheng/2013/_blank"脓疱疮鉴别。

五、治疗：原则：抗病毒、止痛、营养神经、预防感染。动物性皮肤病疥

疮Scabies是由疥螨寄生于人体表皮引起的一种接触性传染性皮肤病，可通过握手、同卧及性接触等密切接触传播，易在集体和家庭中流行。《医学金鉴》称“虫疥”。Scabiesisaninfestationoftheskinwiththemicroscopicmite

Sarcoptesscabei.

Infestationiscommon,foundworldwide,andaffectspeopleofallracesandsocialclasses.Scabiesspreadsrapidlyundercrowdedconditionswherethereisfrequentskin-to-skincontactbetweenpeople,suchasinhospitals,institutions,child-carefacilities,andnursinghomes.一、病因和传播途径：HowdidIgetscabies?Bydirect,prolonged,skin-to-skincontactwithapersonalreadyinfestedwithscabies.Contactmustbeprolonged(aquickhandshakeorhugwillusuallynotspreadinfestation).Infestationiseasilyspreadtosexualpartnersandhouseholdmembers.Infestationmayalsooccurbysharingclothing,towels,andbedding.Howlongwillmiteslive?Onceawayfromthehumanbody,mitesdonotsurvivemorethan48-72hours.Whenlivingonape\t"/kecheng/2013/_blank"/job/rson,anadultfemalemitecanliveuptoamonth.

二、临床表现：Howsoonafterinfestationwillsymptomsbegin?Forapersonwhohasneverbeeninfestedwithscabies,symptomsmaytake4-6weekstobegin.Forapersonwhohashadscabies,symptomsappearwithinseveraldays.Youdonotbecomeimmunetoaninfestation.

1.

丘疹、水疱、隧道、结节。Pimple-likeirritations,burrowsorrashoftheskin,especiallythewebbingbetweenthefingers;theskinfoldsonthewrist,elbow,orknee;thepenis,thebreast,orshoulderblades.2.剧烈瘙痒Intenseitching,especiallyatnightandovermostofthebody.Whoisatriskforsevereinfestation?Peoplewithweakenedimmunesystemsandtheelderlyareatriskforamoresevereformofscabies,calledNorwegianorcrustedscabies.

三、诊断及鉴别诊断：

Howisscabiesinfestationdiagnosed?Diagnosisismostcommonlymadebylookingattheburrowsorrash.Askinscrapingmaybetakentolookformites,eggs,ormitefecalmattertoconfirmthediagnosis.Ifaskinscrapingorbiopsyistakenandreturnsnegative,itispossiblethatyoumaystillbeinfested.Typically,therearefewerthan10mitesontheentirebodyofaninfestedperson;thismakesiteasyforaninfestationtobemissed.根据接触传染史，好发部位，夜间剧痒等不难诊断。若找到疥螨即可确诊。鉴别诊断：应与\t"/kecheng/2013/_blank"痒疹、皮肤\t"/kecheng/2013/_blank"瘙痒症、\t"/kecheng/2013/_blank"虱病、丘疹性\t"/kecheng/2013/_blank"荨麻疹、湿疹等鉴别。

四、预防和治疗：1.隔离消毒。家庭内成员或集体生活者应同时治疗。2.治疗以外用药为主，对瘙痒严重者可辅以镇静止痒药睡前内服。2.并发化脓性感染时，应同时采用抗感染药物治疗。Whoshouldbetreatedforscabies?Anyonewhoisdi