medicine boards certification review case #1 - … antibiotic treatment for purulent ssti ... an 85...
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MedicineBoardsCertificationReview
InfectiousDiseases, Part2LisaG.Winston,MDUniversityofCalifornia,SanFranciscoDivisionofHIV,ID,andGlobalMedicineandDivisionofHospitalMedicineZuckerberg SanFranciscoGeneralHospitalandTraumaCenter
Case#1
32y/oMwith3daysofanenlarging,painfullesiononhisLthighthatheattributestoa“spiderbite”
T36.9BP118/70P82
Howwould youmanagethispatient?
A. Incision anddrainage
B. Dicloxacillin 500mg4x/day
C. TMP-SMXDS1tabtwicedaily
D. Cephalexin 500mg4x/day
Abscesses: I&Dplusantibioticvs.I&DaloneTMP-SMX
TMP-SMXTMP-SMX
p =0.25 p = NS p = 0.12 p = 0.005
RajendranAAC2007;DuongAnnEmerg med2009;SchmitzAnnEmergMed2010;TalanNEJM2016
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Abscesses: I&Dplusantibioticvs.I&Dalone
• Benefits toantibiotics– Slightlyhighercurerates– Decreaseinnewskininfections(short-term)– Talan2016studyalsoshowedlowerratesubsequentsurgicaldrainageanddecreasedinfectionsinhouseholdmembers
Antibiotic therapyrecommended forabscessesassociated with:
• Severedisease
• Signsorsymptomsofsystemicillness
• Immunosuppression
• Extremes ofage
• Difficult todrain area(face, hand, genitalia)
• Failureofprior I&D
Liu C. Clin Infect Dis. 2011
MicrobiologyofPurulentSSTIs
Moran NEJM 2006
OralantibiotictreatmentforpurulentSSTI
Drug AdultDose
TMP/SMX DS 1-2tab twice daily
Doxycycline, Minocycline 100mgtwicedaily
Clindamycin 300-450mg3x/day
Linezolid 600 mgtwicedaily*Rifampin is NOT recommended for routine treatment of SSTIs
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Case#2
28y/owomanpresentswitherythemaofherleftfootoverpast48hrs
Nopurulentdrainage,exudate,orfluctuance.
T37.0BP132/70P78
Howwouldyoumanagethispatient?
A. Watchcloselyfor self-resolution
B. Cephalexin 500mg4x/day
C. Cephalexin 500mg4x/dayplusTMP-SMX1DStwice daily
D. Admit forIVvancomycinwith rapidtransitiontooralantibiotics whenimproved
Cephalexin vs.Cephalexin +TMP-SMXinpatients with Uncomplicated Cellulitis
Pallin CID2013; 56:1754-1762
N=146
Clindamycin vs.TMP-SMXforuncomplicated skininfections
p = 0.38p = 1.00
n = 160 n = 280
MillerNEJM2015
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Treatment ofuncomplicatednon-purulentcellulitis
Drug AdultDose
Cephalexin 500mg 4x/day
Dicloxacillin 500mg 4x/day
Clindamycin* 300-450mg 3x/day
TMP-SMX*(new) 1-2 DStwicedaily
Linezolid* 600mg2x/day*Activity against MRSA
Empiricaltreatmentofcomplicatedskin andsoft tissueinfections
• Admitted tofloor with abscessorcellulitis– I&Dabscess– Vancomycinoralternativeantibiotic(considercefazolinforcellulitis)• Alternative:daptomycin,linezolid,tedizolid,dalbavancin,oritavancin,telavancin,ceftaroline
– NoneedforGramnegativecoverage• Patient admitted toICU/necrotizing fasciitis
– Vancomycinoralternative+Gramnegativecoverage+clindamycin
Case#3:
An85year-oldwomanisadmittedtothehospitalwithaCHFexacerbation.Otherco-morbidconditionsincludediabetesandchronickidneydisease(creatinine=2.5mg/dL).Aurinalysisshows10– 20WBC/HPF.Aurinecultureissentandgrowspan-sensitiveE.coli>100,000cfu/mL.Thepatientdeniesspecificurinarysymptoms.
Whichisthebestcourseofaction?
Case#3:
A. Ciprofloxacin for3daysB. Ciprofloxacin for10daysC. Trimethoprim-sulfamethaxazole for3daysD. Fosfomycinfor1dayE. Nitrofurantoin for7daysF. Noantibiotics
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UrinaryTractInfections
• Uncomplicated cystitis• Women,pre-menopausal,non-pregnant,nourologicabnormalities
• Escherichiacoli70-90%• >35%ampicillinresistance• >20%trimethoprim/sulfamethoxazoleresistanceinmanyareas
• Nitrofurantoin(5days)isgenerallyreliable• IDSAguidelinesrecommendavoidingfluoroquinolones
Guptaetal.Clin InfectDis2011;52(5):e103-120
UrinaryTractInfections
• Recurrent cystitis inwomen (>3x/year)– Dailyor3xweeklyprophylaxis– Post-coitalprophylaxis– Self-treatment forsymptoms
• Selfdiagnosisaccurate– Othermeasures
• Discontinuediaphragmand/orspermicide• Topicalestradiolinpost-menopausalwomen• ?Cranberryjuice
UrinaryTractInfections
• Pyelonephritis– Obtainurineculture– Outpatientinitialrx:fluoroquinolone– Hospitalize
• Inadequatep.o.intake• Severedisease/underlyingillness• Pregnancy
– Initialrxinhospital:fluoroquinolone;aminoglycoside;extended-spectrumcephalosporin(ceftriaxone);extended-spectrumpenicillin;carbapenem• MayswitchtoTNP-SMXifsusceptible
UrinaryTractInfections
• Imaging(U.S.orCT)• Notbetterin72hours• Multipleepisodes• Lowerthresholdinmen
• Tip:remember not tousemoxifloxacin forUTIs
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Case#4:60y.o.womanwithHTNpresentswith3daysofcough
withgreensputum,dyspneaonexertion,fever,pleuriticchestpain.Sheotherwisehasnopastmedicalhistory.
Exam:• 38.5º145/901001895%RA• Chest:cracklesatleftbaseData: WBC:15,500CXR:LLLinfiltrate
• Whatisthemostappropriate treatment?
Case#4:
A. Oralantibioticsathome
B. HospitalizeforIVantibioticsinitially;whenafebrile, switchtooralantibioticsanddischargehome
C. HospitalizeforIVantibioticsinitially;whenafebrile, switchtooralantibioticsanddischargeafter24hoursobservation
D. Hospitalizeforminimumof7daysofIVantibiotics
Pneumonia SeverityIndex
DemographicAge (+1point/yr, -10ifwoman)Nursing home (+10)
ComorbiditiesCancer (+30)Liverdisease (+20)CHF (+10)Cerebrovascular dz (+10)Renal disease (+10)
ExaminationMental status (+20)Pulse >125 (+20)Resp rate>30 (+20)SBP<90 (+15)Temp <35or>40 (+10)
LabspH<7.35 (+30)BUN>30 (+20)Na<130 (+20)Glucose >250 (+10)p02<60 (+10)Hct <30 (+10)Pleural effusion (+10)
Don’t memorize this!
Pneumonia SeverityIndex
Class PSI score Mortality Triage
I Age < 50, no comorbidity, stable vital signs
0.1% outpatient
II ≤ 70 0.7% outpatient
III 71-90 3% consider admission
IV 91-130 8% admission
V > 130 29% ? ICU
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Admissionforcommunity-acquiredpneumonia?
Outpatient:– Younger– Nocancerorend-organdisease
– Noseverevitalsignabnormalities
– Noseverelaboratoryabnormalities
Inpatient:– Doesn’tmeetoutpatienttreatmentcriteria
– Hypoxia– Activecoexistingcondition– Unabletotakeoralmeds– Psychosocialissues
CAP:WhentoDischarge
• Safetodischargewhenafebrile,hemodynamicallystable,nothypoxic,andtoleratingPO
• NominimumdurationofIVtherapyneeded• Noneedtowatchin-hospitalonoralantibiotics• FormostpatientswithCAP,7totaldaysof
antibiotictreatmentisadequate
Case#5:
82y.o.man presentswith5daysofproductive coughand dyspnea. Hispastmedical historyisnotable forCOPD. Denies recenttravelorhospitalization.Exam:
• 39º110/901102485%RA• Chest:cracklesatrightbase
Data:• CXR: Rightlower&middlelobeinfiltrates• Labs: WBC12,000,BUN=38,otherwisenormal
Whatisthemost appropriate treatment?
Case#5:
A. Cefuroxime IVB. Levofloxacin IVC. Piperacillin /tazobactam (Zosyn)IV+
vancomycinIVD. Cefepime IV+tobramycin IV
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EtiologyofCAP
• Clinical syndromeandCXR not predictive oforganism– Streptococcuspneumoniae– Haemophilusinfluenzae– Mycoplasmapneumoniae– Chlamydophilapneumoniae– Legionella– (EntericGramnegativerods)
– Viruses– Staphylococcusaureus(many)
Covered byusual regimes
Not covered byusual regimens
EmpiricalTreatmentforOutpatients
No comorbidity or recent antibiotics
• Macrolide or• Doxycycline
Comorbid condition(s) (age > 65, EtOH, CHF, severe liver or renal disease, cancer, etc.)
orAntibiotics in last 3 months
§ b-lactam (e.g. amoxicillin) + either macrolide or doxycycline
or• Respiratory
fluoroquinolone* * NOT Ciprofloxacin
EmpiricalTreatmentforInpatientsInpatientnon-ICU
§ b-lactam + either macrolide or doxycycline
or• Respiratory fluoroquinolone
Inpatient ICU § b-lactam + either azithromycin or respiratory fluoroquinolone(Penicillin allergy: fluoroquinolone + aztreonam)
Healthcare associated pneumonia
• Antipseudomonal b-lactam or carbepenem + either fluoroquinolone or aminoglycoside
(Controversial and still being revised)
MRSA concern • Add vancomycin or linezolid to above
DiagnosticTestinginCAP• Chestradiography:
– Indicatedforallpatientswithsuspectedpneumonia– Cannotdistinguishatypicalvs.typicalpathogen
• Bloodculture:– Recommendedforsomeinpatients,basedon
severityofillness(beforeantibiotics)• Sputumexam:
– Recommendedforsomeinpatients– Mosthelpfulifsingleorganisminlargenumbers
• Moleculartestingincreasinglyavailable
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Pneumonia:OtherDiagnostics• ConsiderLegionellatestinginsickerpatients
usingrespiratorycultureorurineantigen• Influenzatestingduringinfluenzaseason–
usesensitivetest• Parapneumoniceffusions:
– Small,free-flowingeffusionsdon’tneedtobetapped
– Tapifloculatedorifpatientnotimproving
Case#6A67-year-oldmanwasbroughttotheEDbyparamedicsbecauseofdifficultybreathingandincreasedcoughandconfusion.Thepatienthadcomplainedofcoughwithyellowsputuminthepastthreedaysandincreasingdyspnea.
CXR:Rightlowerlobarinfiltrateandmoderatepleuraleffusion.
Sputum:Manypolymorphonuclearneutrophilsandmanygram-positivecocciinpairsandchains.
Case#6: Case#6
Thepatientwasadmittedandstartedonceftriaxoneandazithromycin.Histemperaturedecreasedto38˚Cafter48hoursandhefeltsomewhatimproved.
Onhospitalday#3,hedevelopedanincreasedtemperature to39˚Candwastachypneicat35breaths/minutewithanoxygensaturationof88%onroomair.Thepatientbecamemoreconfusedandwastransferredtotheintensivecareunit.
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Case#6
Whichof thefollowingshouldbe donenow?A.ChangeantibioticstolevofloxacinB.ChangeintravenouslinesandaddtobramycinC.PerformadiagnosticthoracentesisD.Administerstressdosesofcorticosteroids
ClinicalSyndromesPneumonia gonebad
Whenpneumonia failstorespond toinitialtreatment or getsworse, consider
– Wrongbug– Wrongdrug– Noninfectiousetiology– Complicationsofpneumonia,e.g.empyema– Naturalhistoryofdisease
Pneumococcal Vaccines: - polysaccharide vaccine(PPV23)- Pneumovax- proteinconjugatevaccine(PCV13)- Prevnar
Conditions PCV13 PPV23 PPV23#2
Age ≥ 65years Yes Yes No
Age 19-64withchronicheartorlungdisease(includingasthma),smokers
No Yes No
CSF leakorcochlearimplant Yes Yes No
Functional/acquiredasplenia Yes Yes Yes
Immunocompromised Yes Yes Yes
Case#7:• A70year-oldmanishospitalizedfordiverticulitis.
Heisnearingdischargewhenhedevelopsanewfever. Purulentdrainageisnotedfromacentralvenouscatheter,anditisremoved.Despiteremovalofthecatheter,feverpersistsforseveraldays.Physicalexaminationrevealsanewsystolicmurmur.Echocardiogramshowsasmallvegetationonthemitralvalve.
• WhichorganismMOSTLIKELYgrewfromhisbloodcultures?
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Case#7:
A. StaphylococcusaureusB. StreptococcusbovisC. EnterococcusD. Candida
Endocarditis
• Mostcommon organisms– Staphylococcusaureus (especiallyhealthcare-associated,injectiondruguse)
– Streptococci,viridansgroup;alsoS.bovis– Coagulase-negativestaphylococci(especiallyprostheticvalve)
– Candida– Culturenegative– HACEK
Endocarditis
• Diagnosis: Modified DukeCriteria– Major
• Specificmicrobiologic– usuallybloodcultures• Evidenceendocardialinvolvement
–Newvalvularregurgitation–Specificechocardiographicfindings
– MinorPredisposition VascularphenomenaFever ImmunologicphenomenaOthermicrobiologic
Osler nodes Janeway lesions
Splinter hemorrhages
Roth spots(white-centered
retinal hemorrhages -arrow heads)
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Endocarditis
• Dukecriteriacontinued…– Definiteendocarditis=2major;1major+3minor;5minor;orpathologicallyconfirmed
– Possibleendocarditis=1major+1minor;3minor
• Surgery indications:CHF,continuedsystemicemboli,uncontrolledsepsis,abscess,fungalIE;oftenprostheticvalve,Gramnegativeaerobesandunusualorganisms
Endocarditis - Treatment
• Penicillin-susceptiblestreptococcus– PenicillinGorceftriaxonex4wk– PenicillinGorceftriaxone+gentamicinx2wk
• StreptococcusMIC>.1to.5µg/mL– PenicillinGorceftriaxonex4wk+gentamicinx2wk
• Penicillin-susceptibleenterococcus– AmpicillinorpenicillinG+gentamicinx4-6wk– Ampicillin+ceftriaxonex6wk
Use recommended regimens!
Endocarditis - Treatment
• NativevalveMSSA– Nafcillinoroxacillinorcefazolinx6wk
• NativevalveMRSA– Vancomycinx6wk– Daptomycinx6wk
• HACEK– Ceftriaxonex4wk– Ampicillinx4wk(ifsusceptible)
Baddour Circulation2015
Endocarditis - Prophylaxis
• CurrentguidelinesfromAmericanHeartAssociation2007
• Verydifferentfrompreviousguidelinesupdatedin1997
• Prophylaxisonlyforpatientswithhighestriskforadverseoutcomes:– Prostheticvalve,previousendocarditis,cardiactransplantationwithvalvulopathy,certaincongenitalheartdisease
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Endocarditis - Prophylaxis
• Forcardiacconditionsonpreviousslideonly,prophylaxisfordentalprocedureswithmanipulationofgingivaorperiapicalregionofteethorperforationoforalmucosa
• NoprophylaxisGIorGUproceduresforpurposeofpreventingendocarditis
WilsonCirculation2007
Case#8:
• A40year-oldwoman whoreturned 2daysagoaftera3-weektriptoeastAfrica presentswithfever. Shehad beenprescribed mefloquine (Lariam) formalariaprophylaxis butstopped takingitduetoinsomnia. Shedeveloped feverduring theflighthome. Other symptoms include chills, diaphoresis,myalgia,andheadache. Shehas hadno diarrhea.Activitiesincluded frequent hikes,andshe swaminfreshwater1weekbeforeherdeparture.
• YouareconcernedaboutallofthefollowingEXCEPT
Case#8:
A. MalariaB. TyphoidC. Rickettsial infectionD. Acuteschistosomiasis (Katayamafever)
TravelMedicine
• Returned travelerwith afever– Shortincubationperiod(<14days):
• Malaria(especiallyfalciparum)• Dengue• Chikungunya• Zika• Typhoidfever
–Also,non-tropicaldiseases– Incubationperiod>14days
• Malaria:falciparum(~1month)andnon-falciparum• Typhoidfever(3weeks;rarelyupto60days)• Hepatitis,especiallyAandE
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TravelMedicine
• Workupforfever–Right away
• Malaria smears• Bloodcultures(typhoid,meningococcus)• Other,directedappropriateevaluation:e.g.CXRforrespiratorysymptoms
TravelMedicine
• Other teststoconsider– Eosinophilcount– Stoolstudies(diarrheaorelevatedeosinophils)– PCR(dengue,chikungunya,Zika)– Serologies(hepatitis,dengue,chikungunya,Zika,leptospirosis,helminthicinfections)
– HIV– Occasionally,bloodsmearsand/orskinsnips(microfilariae)
TravelMedicine
• Initial therapy– Ideally,etiologydirected– Supportive– Ifvery ill,antibiotics(e.g.ceftriaxone,fluoroquinolone)pendingdiagnosis
– Considerempiricaltherapyifcharacteristicsyndrome• Rickettsialdisease• Leptospirosis
TravelMedicine• Immunizations
– HepatitisA,typhoid– Ifnotup-to-date:tetanus-diphtheria(+/- pertussis),measles
– Dependingondestinationandactivities:hepatitisB,Japaneseencephalitis,yellowfever,polio,meningococcus,rabies
• Diarrhea:– Loperamidetotreatifnon-inflammatory– Considerbismuthsubsalicylateprophylaxis– Okaytogivefluoroquinoloneifsymptomsdevelop
• Alternatives:azithromycinorrifaximin
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Case#9:
• A60year-oldmanwithahistoryofmultiplemyelomaisbroughtinbyhisfamilytotheEmergencyDepartment. Hisfamilyreports1dayofheadache,fever,andconfusion.Thepatientislethargicandunabletoanswerquestions.LumbarpuncturerevealsaWBCcountof800cells/µL,glucose30mg/dL,andprotein150mg/dL.GramstainshowsmanyWBC,noorganisms.
• Whichoneofthefollowinginitialregimensisappropriate?
Case#9:
A. Ceftriaxone, vancomycin,ampicillin, anddexamethasone
B. Ceftriaxone, vancomycin,anddexamethasone
C. Ceftriaxone andvancomycinD. Ceftriaxone, vancomycin,and ciprofloxacin
BacterialMeningitis
• Very serious disease– Morbidityandmortalityremainhigh– Fatalwithoutantibiotics– emphasisonrapiddelivery
– SteroidsindicatedinadultsgivenbenefitforStreptococcuspneumoniae;givebefore—oratleastwith—firstdoseantibiotics
deGans NEJM2002
BacterialMeningitis
• Organisms– Neonates:S.agalactiae,E.coli,L.monocytogenes– Children:N.meningitidis,S.pneumoniae,(H.influenzae)
– Youngeradults(healthy):S.pneumoniae,N.meningitidis
– Olderadults(underlyingdisease):S.pneumoniae,L.monocytogenes
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BacterialMeningitis
• General indications for CTbefore LPwhenmeningitis suspected– Age(>60years)– Immunocompromise– HistoryofCNSdisease(e.g.masslesion)– Recentseizure– Neurologicabnormalities
• Includingfocaldeficitandabnormallevelofconsciousness
– Papilledema
BacterialMeningitis
• Empirical antibiotic therapy– Youngeradults:broad-spectrumcephalosporin(highdose),oftenplusvancomycin– whenatleastmoderatesuspicionpneumococcus
– Olderadults/underlyingillness:asabove+ampicillinortmp/smx(penicillinallergy)
• ProphylaxisforclosecontactsonlyifN.meningitidisandsomecasesH.influenzae
Encephalitis
• Herpessimplexencephalitis– Mostcommontreatableencephalitis– Lowthresholdtoaddacyclovir
• WestNileVirus:3formsneuroinvasive– ageisbiggestriskfactor– Meningitis– favorableoutcome– Encephalitis– alteredlevelofconsciousnessand/orpersonalitychange+CNSinflammation
– Acuteflaccidparalysis– worst
Case#10• An85year-oldwomanisadmittedinJanuarywithfeverandshortnessofbreathfor36hours.Sheliveswithherdaughterandgrandchildren.CXRshowsapatchylowerlobeconsolidation.Sheisintubatedforrespiratorydistressandhypoxemia.TrachealaspirateGramstainshowsPMNsbutnoorganisms.ArapidantigentestisnegativeforinfluenzaAandB.
• Whichmedicationswouldyoustart?
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Case#10:
A. Levofloxacin +azithromycinB. Metronidazole +azithromycinC. Vancomycin +ceftriaxone +rimantidineD. Vancomycin +piperacillin/tazobactamE. Ceftriaxone +azithromycin +oseltamivir
Influenza
• Twotypesofclinical importance: AandB• InfluenzaA
– Infectsanimals;causeofpandemicinfluenza– Previouslywassusceptibletoadamantanesandneuraminidaseinhibitors• Circulatingstrainsresistanttoadamantanes
– Typedbysurfaceglycoproteinshemagglutininandneuraminidase
• Influenza B– notsusceptible toadamantanes
Influenza
• Neuraminidase inhibitors - block cleavagefromhost cellsurface– Oseltamivir– oral– Zanamivir– inhaled– Peramivir– IV
Influenza
• Insusceptible influenza, alldrugsreduceclinical illnessbyabout 1daywhen startedwithin 48hrs.ofsymptoms– Likelyefficaciousforprophylaxis
• Observational datashowmortality benefit forhospitalized patients treated with oseltamivir,evenoutside 48hr.window
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Influenza
• Influenzavaccine recommended foreveryone>6months ofage,unless there isacontraindication (rare)– Starting2016-17,eggallergynolongeracontraindication
InfectionControl
Type of Precaution
Conditions Examples
Contact DiarrheaWoundsVesicular rashesSome resp infections
C. difficile, chickenpox, smallpox, scabies, lice, viral conjunctivitis, drug resistant organisms
Droplet MeningitisSome resp infections
Meningococcus, pertussis
Airborne Some resp infections TB, chickenpox, measles, smallpox, SARS
Case#11:
• A35year-oldmanwhorecentlyreturnedfromHawaii(thebigisland)complainsoffever,myalgia,andheadache.Conjunctivalsuffusionisnoted.Hereportsthatheswaminafreshwaterpond,althoughtherewasasignpostedthatswimmingwasnotadvisable.Hewondersifthiscouldhaveanythingtodowithhiscurrentillness.
• Whattherapyisnowappropriate?
Case#11:
A. CephalexinB. ChloramphenicolC. PenicillinD. Gentamicin
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Potpourri
• Leptospirosis– Biphasicillness(renal/hepaticinvolvementsecondphase)– Jarisch-Herxheimerreactionpossible
• Lymedisease– Borreliabergdorferi spreadbydeertick(nymphal)– Prolongedattachment(48-72hrs)– Clinicaldiagnosis:erythemamigrans– PEPwithdoxycyclineiseffectivebutonlyindicatedifsubstantialrisk
– ProlongedIVtherapyforchronicsxsineffective
Potpourri
• Other Borrelia– Tick-bornerelapsingfever
• BorreliahermsiithoughttobemostcommoncauseinU.S.
– Outdoorexposure,westernU.S.• Linkedtosleepinginrusticcabins
– Examinebloodsmearduringfeverforspirochetes– Treatwithdoxycycline(Jarisch-Herxheimerrxncommon)
Potpourri
• RecognizeRockyMountainspottedfever• Transmittedbyticks(mostlyDermacentor– dogandwoodticks);latespringandsummer– EspeciallySouthAtlanticandEastSouthCentralstates
• AgentisRickettsiarickettsii• Classicpetechialrashnotinallpatients,notalwaysonpalmsandsoles– Maynotappearuntil3-5daysafterfever
• Treatwithdoxycycline– lowthreshold• Diagnosisusuallyconfirmedretrospectivelywithserology
Potpourri• EhrlichiosisandAnaplasmosis
– EhrlichiachaffeensisandE.ewingiitransmittedbylonestartickinsoutheasternandsouthcentralU.S.• Mayseerash
– AnaplasmaphagocytophilumtransmittedbyIxodes (deer)tickinuppermidwest,northeast,northernCA• Morelikelytoseemorulae(inclusions)• Rashuncommon
– Fever,headache,myalgia;leukopenia,thrombocytopenia,elevatedAST/ALT
– Diagnosedbasedonantibodytiters– Treatwithdoxycycline
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Potpourri
• Differential diagnosis ofnodularlymphangitis– Sporothrixschenckii– Mycobacteriummarinum– Nocardiabrasiliensis– Othermycobacteriaandotherorganisms(rarely)
– Don’tforget:GroupAstreptococcus,especiallyifmoreacute;S.aureus
Potpourri
• Erysipelothrix– Grampositiverod– “Fishhandler’sdisease”– Treatwithpenicillin(manyotherantibiotics)
• Vibrio vulnificus– Sepsisandcutaneouslesionsinimmunocompromisedhost(esp.cirrhosis)aftereatingoysters
– Cellulitisafterexposuretoseawater– Antibioticsmayincludeceftazidime,doxycycline,ciprofloxacin
Potpourri
• Anthrax– Severe illness– Widenedmediastinum,meningitis,earlypositivebloodcultures
– UlcerafteranimalcontactorBTscenario
Potpourri
• Tularemia– Ticks/bitingflies;animalcontact(e.g.skinning);airbornetransmission
– Rabbitsandothersmallmammalsarereservoir– Presentationoftendependsonmodeoftransmission:e.g.glandular/ulceroglandularfromtickbite,pneumonicfrombrushcutting,alsotyphoidalform
– Notifylabifsupected– canbetransmittedfromculture– Rx:streptomycin(preferred),gentamicinalternate;fluoroquinolonesactive;tetracyclinescanbeusedwithmilderillness• Chloramphenicolusedformeningitis– maybedifficulttoobtaininU.S.
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Potpourri
• Babesia– Tick-borne,intraerythrocyticprotozoa– Symptomaticwithsplenectomy,immunecompromise,olderage
– Canbeco-transmittedwithLyme– “Maltesecross”(tetrads)– Treatment withatovaquone+azithromycinorquinine+clindamycin
Miscellaneous Tips:
• Withuncommondiseases,classicpresentation• Considerdoxycyclinedeficiency• Chloramphenicol:notlikelytheanswer• Reviewtick-borneillnesses• Reviewsyphilis• Typically,limitedHIV• Nothingcontroversialorbrandnew