Добавил:

Sekretar kiopkiopkiop18@yandex.ru t.me/Prokururor I Вовсе не секретарь, но почту проверяю Опубликованный материал нарушает ваши авторские права? Сообщите нам.

Вуз:

Ростовский Государственный Медицинский Университет

Предмет:

Медицина общая

Файл:

Книга_5200_Библиотеки_им_академика_М_И_Перельмана

.pdf

Скачиваний:

Добавлен:

30.08.2026

Размер:

52 Мб

Скачать

☆

<<< < Предыдущая 22 23 24 25 26 27 28 29 30 31 32 3334 / 5034 35 36 37 38 39 40 41 42 43 44 45 46 > Следующая >>>

flaresanduseofadjunctivetherapiesandapproaches.JournaloftheAmericanAcademyofDermatology,71(6),1218–1233.

Souto,E.B.,Dias-Ferreira,J.,Oliviera,J.,etal.(2019). Trendsinatopicdermatitis-fromstandardpharmacotherapytonoveldrugdelivery

systems.InternationalJournalofMolecularSciences,20(22),5659.

Fungal,Viral,andBacterialInfectionsoftheSkin

ImanI.Aberra,VirginiaP.Arcangelo,andJasonJ.Schafer

LearningObjectives

1. Recognize signs, symptoms, and presentation ofvarious types of bacterial, fungal, and viral skin

infections.

2.Identifythecausesandriskfactorsfordifferenttypesofskininfections.

3. Create a treatment plan including pharmacologic, nonpharmacologic, and preventive measures for

skininfections.

INTRODUCTION

Skininfectionsare commonproblemsthatwill causepatientstoseekmedical attention.Bacterialskin infections can become a life-threateninginfectionifnotpromptly andappropriately treated. Viral and fungalinfectionscanbecontagious,andpatientsshouldbecounseledonappropriatepreventivemeasures toreducetransmissiontoothers.

BACTERIALSKININFECTIONSIntroduction

Bacterialskininfectionsrangefromthosethatareminorandhealwithoutconsequencetothosethatare moresevereandmaybedisfiguringorevenlifethreatening.Minorinfectionsarequitecommonandare oftenself-treatedbypatientswithoutformalmedical care.Themajorityofwoundsseeninhealthcare practiceareeasilymanagedwithappropriatewoundcareandantibiotictherapy,ifindicated.

Common primary skin infections resulting from bacteria include impetigo, bullous impetigo, folliculitis,felons,paronychias,andcellulitis.(SeeBox13.1forinformationaboutassociatedproblems.) Thesearediscussedinthischapter,alongwiththelesscommoninfectionserysipelas,ecthyma,furuncles,

and carbuncles. This chapter also contains a brief discussion of necrotizing fasciitis, a very serious infectiontreatedinaninpatientsettingbyspecialists.

Causes

Bacteria most commonly responsible for causingskininfectionsare Staphylococcus aureus andbetahemolytic streptococci such as Streptococcus pyogenes (group A Streptococcus, or GAS) and

Streptococcusagalactiae(groupBStreptococcus,orGBS)(Tables13.1and13.2).

ImpetigoandEcthyma

Impetigois a commonsuperficial skininfectioncharacterized byscattered vesicularlesions dueto S. aureus,GAS,orboth.Bullousimpetigo,avariationofimpetigowhereblistersorbullaeform,iscaused

primarily byS. aureus. Ecthyma is a chronic formof impetigothataffects deeper layers of the skin. Ecthyma can develop from minor wounds, scabies, insect bites, or any condition that causes itching, scratching,andexcoriation.

Impetigoismorecommoninchildrenbutcanalsobeseeninadults.Hotandhumidweatherpromotes growth of bacteria on the skin and can result in these infections. Both impetigo and ecthyma are communicable and can be transmitted through person-to-person contact, often in schools or day care centers. Poor hygiene and crowded living conditions are other factors that can contribute to the developmentoftheseinfections.

Box13.1 Danger:BitesandOtherPunctureWounds

Humanandanimalbitesandpuncturewoundsofothersortsareinfectionswaitingtodevelop.Because these wounds areassociated withsuch a highrisk for infection,antibiotic prophylaxis withbroadspectrum penicillin usually begins with the patient’s request for health care. Tetanus is also an important consideration in puncture wounds and bites, and patients should be immunized as appropriate.Ifpatientsareunsureofwhentheirlasttetanusvaccinewasdone,itisbesttoerronthe sideofcautionandgivethetetanusvaccine.

Ifthewoundwascreatedbyacleanobjectandisinanareathatiswellvascularized,treatmentmay consist simply of washing thoroughly; soaking in warm, soapy water several times a day; and observingthesiteforafewdays.

Ifthewoundwasmadebyanobjectcontaminatedwithfecalmaterial,soil,orotherdebris,orifthe patient is diabetic or has a compromised circulation, antibiotics should be initiated based on the probablecausative organism. Thesepatients mayneed closeobservationto ensure thattheydo not developasystemicinfection.

Careforbitewoundsdependsonseveralfactors,includingwhetherthebitewasfromahumanoran animal,thelocationofthewound,andwhetherthewoundisprimarilyapunctureoralaceration.All bitewoundsshouldbecleanedthoroughlywithsoapandwater.Puncturebitesshouldbeirrigatedwith normalsalinesolution.Extensivewoundsmayrequiresurgicaldebridement,tendonrepair,orsuturing. Ifthebiteislocatedonanextremity,elevationoftheextremitywillhelppreventswelling.

Allhumanbitesthatbreaktheskinshouldbetreatedwithantibiotics.Appropriatechoicesinclude

oralamoxicillin–clavulanateorampicillin–sulbactamforIVtreatment.OralorIVdoxycyclinecanbe usedforpatientswhoareallergictopenicillin.Treatmentshouldbegivenfor3to5days.

Minoranimalbitesmaynotrequireantibiotictherapyunlessthewoundisonthehand,foot,orface. Patients who are immunocompromised should betreated withantibiotics. The possibilityof rabies mustalsobeaddressed,andlocalhealthofficialsmayneedtobecontactedtodeterminetheneedto administerpost-exposurerabiesvaccinationtothepatient.Thesameagentsusedforhumanbitesare alsoappropriateforanimalbites.

Althoughmostpuncturewoundshealwithoutincident,patientsshouldbeinstructedtoobservefor signsofinfection,includinginflammation,persistentpain,swelling,orpurulentdrainage.Ifapuncture woundbecomesinfected,furthersystemicantibiotictherapyisrequiredandshouldbebasedonGram stainandcultureresults.Afollow-upvisitshouldbescheduledwithindaystoensurethatthewoundis healingwithoutfurtherinfection.

Source:Stevens,D.L.,Bisno,A.L.,Chambers,H.F.,etal.(2014).Practiceguidelinesforthediagnosisandmanagementofskinandsoft tissueinfections:2014updatebytheInfectiousDiseasesSocietyofAmerica.ClinicalInfectiousDiseases:AnOfficialPublicationof theInfectiousDiseasesSocietyofAmerica,59(2),e10-e52.

TABLE13.1

SelectedOrganismsThatCauseSkinInfections

CellulitisandErysipelas

Cellulitisisaninfectioninvolvingthesubcutaneoustissue.Ithasthepotentialtospreadsystemicallyand causeseriousillness.Itcandevelop fromanytypeofskinbreakageincludingthosethatare notvisibly noticeable.Examplesofconditionsthatmaycauseskinbreakageincludevenousinsufficiency,edema,and obesity.Inintravenous(IV)drugusers,cellulitistypicallydevelopsatinjectionsites,andpatientsareat riskfordeep-seededinfection.Thecharacteristicsofinfectiondependonmanyfactors,includingthetype ofwound,theorganismsinvolved,andthepatient.

Mostcasesofnon-purulentcellulitisare causedbyGAS.Patientswithcertainpredisposingfactors,

however,maybeatriskforinfectionscausedbyotherorganisms.Pasteurellamultocidaistheprimary causeofcellulitisfromanimalbitesandscratches.Table13.2listsadditionalcauses.

Methicillin-resistantS.aureus(MRSA)infectionscanbeparticularlychallengingtomanagebecause

commonlyusedantibioticssuchaspenicillinsandcephalosporinsareinactiveagainstMRSA.Thoseat riskforMRSAinfectionsarethosewithpenetratingtrauma,otheractiveMRSAinfection,positiveMRSA nasalswab,IVdruguse,purulentdrainage,orseptic(severenon-purulentinfection).

TABLE13.2

BacteriaThatCanCauseCellulitisUnderCertainConditions

Organism Condition

Staphylococcusaureus Common GroupAStreptococcus Common HaemophilusinfluenzaeB Children(periorbitalcellulitis*) GroupBStreptococcus Newborns

Escherichiacoli Opportunisticincompromisedpatients Pseudomonasaeruginosa Folliculitisfromunder-chlorinatedhottubs

Burns

Klebsiellaspecies Opportunisticincompromisedpatients Enterobacterspecies Opportunisticincompromisedpatients Pasteurellamultocida Animalbitesandscratches

Anaerobicorganisms Diabetes,ulcers,trauma,crushwounds

Aeromonashydrophila Freshwater-relatedinjury,immunosuppressedpatients Vibriospecies Seawater-relatedinjuries,woundcontactwithraworundercookedseafood

*UncommonnowbecauseoftheuseoftheHIBvaccine.

Erysipelas,predominantlycausedbyS.pyogenes,occursinthesuperficialepidermisandisseenmore

ofteninchildren,especiallyinfants,andolderadults.

PurulentSkinInfections

Pustular infections include abscesses, folliculitis, furunculosis, and carbunculosis and are commonly causedbyS.aureus.Abscessesaresometimespolymicrobialdependingwhereonthebodyitforms.A majorityofcasesareduetoMRSA.

Folliculitis is a superficial infection of the hair follicle. Pseudomonas aeruginosa can also cause

folliculitis, particularly in those who frequently use hot tubs, as a result of inadequate chlorination. Furunculosis(furuncles)andcarbunculosis(carbuncles)involvedeeperareasoftheskinandcandevelop fromunresolvedcasesoffolliculitis.

Irritationfromshaving,plucking,andwaxingofhairmaycontributetofolliculitis.Otherpredisposing factorsincludehumidconditions,tightclothing,diabetes,occlusionofthehairfolliclesfromcosmeticsor sunscreens,poorhygiene,andoccupationalexposuretoheavygreaseorsolvents.

Other commonskininfections,suchas acuteparonychia(aninfectioninatleastonenailfoldofthe fingers or toes) and a felon(a finger infection onthepalmside), are usuallycaused byS. aureus, S. pyogenes,orPseudomonasspeciesandoccasionallyothergram-negativebacilli.Womenareatmorerisk forthesetypesofskininfectionsperhapsbecauseoftheirmorefrequentutilizationofnailservices.

DiabeticFootInfection

Diabetescancausemanymicrovascularandmacrovascularcomplications.Thebestwaytomitigatethe risk for developing these complications is to maintain good glycemic control. A microvascular complicationthatcanbeadevastatingandrecurringproblemisdiabeticfootinfection(DFI).

It isestimatedthat 25% ofpeople withdiabetes will develop a DFIatleast once in their lifetime (Barwell et al., 2017). DFIs increase the likelihood of needing an amputation and therefore affecting

quality of life. It is associated with prolonged hospital stay and both physical and psychological morbidity (Barwell et al., 2017). Risk factors in patients with diabetes include neuropathy, foot deformities,peripheralarterydisease(PAD),increasedageanddurationofdiabetes,ethnicminority,illfittingshoes, other microvascular complications including renal dysfunction, and past foot ulcerations (Boultonetal.,2018).

NecrotizingFasciitis

Necrotizingfasciitisisanextremelyseriousinfectionofthesubcutaneoustissuesbetweentheskinandthe underlyingmuscle.Itcanbelifethreateningifnotdiagnosedearlyandtreatedappropriately.Management requiresemergentsurgicalinterventionstoremoveinfectedtissueincombinationwithantibiotictherapy. Riskfactorsfordevelopingnecrotizingfasciitisincludealcoholabuse,diabetes,severedebilitation,and trauma.Mortalityishigh,especiallyifsurgicaldebridementisdelayedorincomplete.

Necrotizingfasciitistype1isapolymicrobialinfectiontypicallyincludingmanyaerobicandanaerobic organisms. Itis commonly associatedwith perianal abscesses, penetratingtrauma,complicated bowel procedures,decubitusulcers,Bartholinabscess,andepisiotomywounds.

Necrotizingfasciitistype2ismonomicrobial,mostcommonlyinvolvingGAS,althoughS.aureus,and anaerobicbacteriasuchasPeptostreptococcus,canalsobethecause.Insomecases,GASandS.aureus cancausenecrotizingfasciitisaloneasamonomicrobialinfection.Varicellainfectionisconsideredarisk factorforinvasiveskininfections,includingnecrotizingfasciitiscausedbyGASandrarelyMRSA.

Necrotizingfasciitistype3,orgasgangrene,isoftencausedbyClostridiumperfringens,ananaerobic bacteriumcommonlyfoundinsoil.Thiscanoccurfollowingdeeppenetratingtraumainjuries.

Pathophysiology

Theskiniscomposedofthreelayers.Theouterlayeristheepidermis,thefirstlineofdefenseagainst infection.Nailtissueispartoftheepidermis.Underneathisthedermis,whichcontainsconnectivetissue, blood vessels, nerves, hair follicles, sweat glands, and sebaceous glands. The innermost layer, hypodermis,iscomposedofsubcutaneoustissue.Skininfectionsmaybeclassifiedaccordingtothedepth ofpenetrationandthelayerandskinstructureaffected.

Undernormalcircumstances,bacteriapresentontheskinasnormalfloracausenoharm.However,a break inthe skin can allow these organisms to penetrate and proliferate, resultingin a skin infection. Some people are persistent carriers of S. aureus in the nasal, perineal, or axillary areas. These individualsmaybemorepronetodevelopingskininfectionsandmorelikelytoexperiencerecurrences.

Patientswithpredisposingmedicalconditions(Box13.2),suchasdiabetes,immunesystemdisorders, andmalnutritionfromalcoholismorothercauses,aremorepronetoskininfectionbecauseofpoorwound healing.Also at a higherriskfor skininfectionarethosewith circulatorycompromise ofthearterial, venous,orlymphatic systems.Wound infections inpatients withtheseconditions havethepotential to become more serious and invasive, requiring IV antibiotic therapy, hospitalization, or referral to a specialist.Woundinfectionscanalso becomemoreseriouswhentreatmentisdelayed.Thepractitioner mustbealertforthesesituationsandactpromptly.

Inaddition,manyorganismsasidefromGASandS.aureusmaycauseskininfectionsinpatientswith chronicconditionslikediabetes.TheseorganismsincludeEscherichiacoli(E.coli),Klebsiellaspecies, andP.aeruginosa.Infectionsinthesepatientsareoftenmoredifficulttomanageclinicallyandhavethe tendency to become chronic. Infections that do resolve with appropriate therapy have a high risk of

recurrence.AcommonexampleofthisscenarioisaDFI.

Box13.2 PredisposingFactorsinSkinInfections

ChroniccarriersofStaphylococcusaureus Diabetesmellitus Debilitation Peripheralvasculardisease Venousstasis Alcoholism(malnutrition) Immunedeficiency Corticosteroidtherapy Obesity Traumaorburns Poorhygiene Warm,humidconditions Topicalirritants Tightclothing

DiagnosticCriteria

ImpetigoandEcthyma

Impetigo,ahighlycontagious,commonprimaryskininfectioninchildren,ismostfrequentlyfoundonthe face,scalp,orextremities.Itbeginsasscattered,discretemaculesthatitchandarespreadbyscratching. Thesemaculesthendevelopintovesiclesandpustulesonanerythematousbasethateventuallyrupture, oozingapurulentliquid.Oncedried,thelesionsappearthick,withacharacteristichoney-coloredcrust onthesurface.Oncehealed,scarringisrare.Regionallymphadenopathymaybepresent,andlesionsmay itch;however,feverorothersystemiccomplaintsareuncommon.Theinfectionisdiagnosedclinicallyby theappearanceofhallmarkhoney-colored crusts.Althoughnotcommonlydoneinpracticeduetotime restrictions,gramstainandcultureofthepusorexudatestoidentifyifthecauseisfromS.aureusorGAS are recommend by the Infectious Diseases Society of America (IDSA). It is acceptable, however, to proceedwithtreatmentwithoutthesetests.

Impetigomayalsopresentwithbullouslesionsandcanbereferredtoasbullousimpetigo.Foundon the face, scalp, extremities, trunk,and intertriginousareas, it affectsprimarily newborns andchildren undertheageof2.Bullousimpetigoischaracterizedbytheformationofsuperficial,flaccidbullaeonthe skin.Thebrownish-graylesionsaresometimescrustedorhaveanerythematoushalo.Theyalsoappearto besmoothandshiny.

BothtreatedanduntreatedimpetigocausedbynephrogenicGAScandevelopintopoststreptococcal glomerulonephritis. It presents as acute kidney injury, usually 2 to 6 weeks after the occurrence of impetigo.

Ecthymaoccurswhenacaseofimpetigoworsensandspreadsdeeplytothedermis.Muchlesscommon

thanimpetigo,ecthymausuallyaffectsthelowerextremitiesofdebilitatedindividualsandolderadults.It beginswiththeformationofvesiclesthatthendevelopintoshallowulcerations.Theulcerationsenlarge overseveraldaysandaresurroundedbyanerythematoushalo.Becausetheinfectionaffectsthedeeper layersoftheskin,scarringisoftenseenafterulcerationsheal.Lesionsareusuallypainfulandmaypersist forweekstomonths.

CellulitisandErysipelas

Cellulitis isa potentiallyseriousinfectioninvolvingtheskinandsubcutaneoustissue.Thediseasecan spreadthroughthesuperficiallayersofskinandcausepainfulerythema,withtheaffectedareawarmand tendertothetouch.Pittingedemacanalsobepresent,andtheskinmaybepink,shiny,andresemblethe surfaceofan“orangepeel.”Themarginsofcellulitisarediffuse,notsharplydemarcated,andtheaffected areaisflatandusuallyedematous.Inopenwounds,purulentdrainageandnecrosismaybepresent.Red streaks may develop proximal to the area of infection, indicating lymphatic spread or lymphangitis. Systemicsymptomsoffever,chills,andmalaiseandregionaladenitisarealsocommonandcanindicate bacteremia,inwhichcase,bloodculturesshouldbeobtained.

Blood cultures should also be obtained in those who are immunocompromised, are neutropenic, or haveimmersioninjuriesoranimalbites.Culturesofaspirates,biopsies,orswabsmaybeconsideredin thispopulation.Inallothercasesofcellulitis,thesestudiesarenotroutinelyrecommended.

Erysipelas is mostcommonlyfoundonthelowerextremitiesbutcanalsobepresentonthefaceand scalp.Erysipelasbeginsasanareaofsharplydemarcatederythemathatspreadsrapidlyoveraperiodof minutestohours.Theaffectedareaisraised,red,firm,warm,andtendertothetouch.Erythemaspreads alonglocallymphaticchannels,whichgivestheskinatypical“orangepeel”appearanceduetolymphatic obstruction.

Commonsystemicsymptomsincludepain,malaise,chills,andfever.Erysipelasoccurringontheface often follows a streptococcal sore throat infection. The face is usually so inflamed that the eyes are swollenshut.

PurulentSkinInfections

Abscessesarelocalizedcollectionsofpuslocateddeepwithinthedermis.Theyaretendertothetouch, often accompanied with painful erythematous swelling. The swelling is usually firm at first but then becomesfluctuant.

Folliculitisissuperficialandoccursonthehairyareasoftheskin,especiallythebeardedpartsofthe faceandtheintertriginousareas.Earlylesionsappearasclustersofsmall,erythematous,pruriticpapules thatmayquicklyturnintopustules.Eachpapuleorpustulecontainsasinglehairfollicleinitscenter.

Afuruncleorboil,whichdevelopsfromfolliculitis,isapainful,pus-fillednodulethatencirclesahair follicle.Commonsites aretheneck,face,axillae,forearms,upperback,groin,buttocks,andthighs.A carbuncleisaconfluenceofseveralfurunclesthatformdeepwithinthedermis.Theyarebiggerandform deeper in the skin. Common sites of infection are the upper back, neck, or lateral thigh. Systemic manifestationsarenotusuallyseenwithfuruncles,butcarbunclesarefrequentlyaccompaniedbysystemic signs such as fever, malaise, and headache. Cultures of the pus from carbuncles and abscesses are recommendedforseverecases,althoughtreatmentshouldnotbedelayedifobtainingthespecimensisnot feasible.

A paronychia is an infection of the tissue surrounding a nail bed. It is associated with nail biting,

hangnails,orfingersucking;itmayoccurinpeople whohavetheirhandsinwater frequently.Diabetic patientsarealsoatahigherrisk.Aparonychiainvolvingthetoenailmostoftenresultsfromaningrown nail. The infected area appears red and swollen and is painful. Pus, which may accumulate, may sometimesbeexpressedwithgentlepressure;thisusuallyrelievesthediscomfort.Systemicsymptomsare uncommon.

Afelon,whichmayfollowafingertipwound,isaninfectionthatinvolvesthepulpspaceinthetipofa digit. It is potentially more serious than a paronychia because it is confined in a closed space. The affected digit is erythematous, edematous, and exquisitely tender. The edema has the potential to compromisethearterialsupplyofthedigit.Ifleftuntreated,abscessandtissuenecrosis canoccur.An additionaldangeristhepossibilityofbonyorjointinvolvement,whichcanleadtolossoffunction.

DiabeticFootInfection

Itisimportanttorealizethatnotalldiabeticfootulcersareinfected.Itisessentialtomakethisdistinction asgivingantibioticsunnecessarilycanharborresistantorganismsthatmakefutureinfectionsdifficultto treat.Ulcers thatshowpurulenceor atleasttwosignsofinflammationare deemedinfectious.Signsof inflammationincludeerythema, warmth,tenderness,pain,andinduration.Other signs canincludenonpurulent secretions, discolored granulation tissue, and foul odor (Lipsky et al., 2012). A validated classificationsystemshouldbeusedtoclassifytheseverityofinfection,whichwillaidintreatment.An exampleofavalidatedclassificationsystemis theonedeveloped bytheIDSA(Table13.3). All other causesofinflammationoftheskinshouldberuledout,suchasgout,distalvenousthrombosis,andvenous stasis.PADshouldbeevaluatedandforsevereinfectionsvascularsurgerymayneedtobeconsultedto evaluateforlimbischemia.

Tissuecultureshouldbeobtainedfrominfectiouswoundsafterdebridementandcleansingandpriorto initiatingantibioticsifpossible.Purulentsecretionsshouldbeaspiratedifpossibleandsentforculture. Woundswabsshould be avoidedastheycanbe contaminatedwithnormalskinflora andwillbe less accurateinidentifyingthepathogenic organism.MildDFIsinpatientswhohavenotrecentlyreceived antibioticsdonotneedculture.Insevereinfections,culturescanbetakenintheoperatingroomifthereis needforextensivedebridement.

TABLE13.3

InfectiousDiseasesSocietyofAmericaClassificationofDiabeticFootInfection

Classification Manifestation

Noninfectious Nosignsorsymptomsofinfection. Mild Localinfectionwithoutinvolvementofdeepertissues.

Iferythemaispresent,itshouldbe>0.5cmto≤2cmaroundtheulcer.

Moderate Localinfectionwitherythema>2cmorinvolvingstructuresdeeperthanskinandsubcutaneous

tissues.

Severe Localinfection(asdescribedpreviously)withthesignsofSIRS,asmanifestedby≥2ofthe

following:

•Temperature>38°Cor<36°C

•Heartrate>90bpm

•Respiratoryrate>20breaths/minorPaCO2<32mmHg

•Whitebloodcellcount>12,000or>4,000cells/mcLor≥10%immature(band)forms

SIRS,systemicinflammatoryresponsesyndrome.

AdaptedfromtheInfectiousDiseasesSocietyofAmericaDiabeticFootInfectionGuidelines,2012.

PatientspresentingwithaDFIshouldhaveradiographstakentoruleoutosteomyelitis,gasformation, oranyotherabnormalitiesonthefoot.IfX-rayimagingcannotruleoutosteomyelitis,additionalimaging withmagneticresonanceimaging(MRI)needstobeperformedtoruleoutboneinvolvementasthatwill affectthedurationanddosingofantimicrobials.

NecrotizingFasciitis

Patients with necrotizing fasciitis are extremely ill, requiring intensive care and emergent surgical debridement.Theinfectionmayinitiallyappearsimilartocellulitis,althoughexcruciatingpain,erythema, andedemaarecommonlypresent.Necrotizingfasciitismaybedifferentiatedfromcellulitisbyitsrapid spread,tissuedestruction,andlackofresponsetousualantibiotictherapy.Thesubcutaneoustissuewill haveawooden-hardfeel,ascomparedtocellulitis anderysipelas,wherethistissueisusuallyyielding andcanbepalpated.Asthisinfectionprogressesandtissuedestructionspreads,painmaybereplacedby anesthesiaduetonecrotizedsuperficialnerveendings,andpatientsmayshowsignsofsepsis,including hemodynamic instability and multiorgan dysfunction. There mayalso be crepitus,bullous lesions,and ecchymoses.

MRIcanbedonetolookforedemaalongthefascia,althoughthisshouldnotdelaytreatment.Diagnosis ismadebyclinicaljudgment.Diagnosisisconfirmedduringsurgicalexplorationofthesite.Thefascia will appearswollenandgraywithareasof string-likenecrosis.Culturesofthedeep tissueshould be obtainedwhileinsurgery.Itisimportantnottotakesuperficialskinculturesastheorganismsthatgrow willnotbetrulyreflectiveoftheorganism(s)inthedeeptissue.

InitiatingDrugTherapy

An increasing challenge in treating skin infections is the problem of antibiotic-resistant organisms. Choosing the appropriate agent is not as simple as it once was, and prescribers must be aware of resistance,aswellasregionalvariationsintheprevalenceandsusceptibilityofinfectingorganisms.

Because warm, humid conditions and poor hygiene may play a role in skin infections, especially impetigo,treatmentbeginswithgoodhygiene(Box13.3),avoidanceofirritants,andmeticulouswound careasappropriate.For someveryminorinfections,thesemeasuresalongwithatopicalagentmaybe sufficient.Adjunctivetreatmentformostskininfections(e.g.,bullousimpetigoanderysipelas)includes warm soaks and elevation of the affected area if the infection involves an extremity. However, most bacterialskininfectionsrequiretreatmentwithsystemicantibiotics.

Themajorityofinfectionsaretreatedintheoutpatientsettingwithoralantibioticagents.Patientswith moreserious infections, however,mayrequire hospitalization, IVantibiotics, andconsultationwithan infectious diseases specialist. Treatment decisions are based on the practitioner’s knowledge of the patient’spredisposingconditionsandpresentationandthetypeandstageoftheinfection.

Box13.3 StrategiestoPreventSkinInfections

Washhandsfrequentlywithsoapandwateroranalcohol-basedhandgel, especiallyafter touching

infectedskintopreventspreadofinfectingorganisms.

<<< < Предыдущая 22 23 24 25 26 27 28 29 30 31 32 3334 / 5034 35 36 37 38 39 40 41 42 43 44 45 46 > Следующая >>>

Соседние файлы в папке Библиотека им академика М.И. Перельмана

#
30.08.202662 Мб0Книга_5196_Библиотеки_им_академика_М_И_Перельмана.pdf
#
30.08.202661 Мб0Книга_5197_Библиотеки_им_академика_М_И_Перельмана.epub
#
30.08.202661 Мб0Книга_5198_Библиотеки_им_академика_М_И_Перельмана.pdf
#
30.08.202659 Мб0Книга_5199_Библиотеки_им_академика_М_И_Перельмана.pdf
#
29.08.202689 Мб0Книга_520_Библиотеки_им_академика_М_И_Перельмана.pdf
#
30.08.202652 Мб0Книга_5200_Библиотеки_им_академика_М_И_Перельмана.pdf
#
30.08.202652 Мб0Книга_5201_Библиотеки_им_академика_М_И_Перельмана.epub
#
30.08.202651 Мб0Книга_5202_Библиотеки_им_академика_М_И_Перельмана.epub
#
30.08.202651 Мб0Книга_5203_Библиотеки_им_академика_М_И_Перельмана.pdf
#
30.08.202647 Мб0Книга_5204_Библиотеки_им_академика_М_И_Перельмана.pdf
#
30.08.202644 Мб0Книга_5205_Библиотеки_им_академика_М_И_Перельмана.pdf