Malignant Otitis Externa

OPAT - Nottingham University Hospitals NHS Trust

DrFionaAndrewarthaConsultantMicrobiologistandInfectiousDiseasesPhysician

BSAC-OPATConference2017

Background •  Externalauditorycanalandskullbaseinvasiveinfection•  86-90%casesindiabetics(RubinGrandis,Branstetteretal.2004)• Pseudomonasaeruginosa>90%cases(RubinandYu1988)• AuralwaterexposurelinkedtoMOE(FordandCourteney-Harris1990;Zikk,Rapoportetal.1991)

•  Clinicalfeatures•  Intractableheadache•  Otalgia•  Otorrhea•  Inflammation,floorofearcanal•  Unresponsivetotopicalantibiotics

•  Complicationsofinvasiveinfection•  Cranialnervepalsies•  VenousSinusThrombosis•  Meningitis•  BrainAbscess

LiftedfromRubinGrandisJ,BranstetterBFt,YuVL.Thechangingfaceofmalignant(necrotising)externalotitis:clinical,radiological,andanatomiccorrelations.TheLancetInfectiousdiseases.2004;4(1):34-9.

Diagnostic Challenges

•  Nosinglepathognomonicfeature•  Typicalsignsofinfectionoftenabsent•  Diagnosisoftendelayed–6.9monthstodiagnosis(JacobsenandAntonelli2010)•  ESRreportedtobeuseful(Rubin,Stoehretal.1989)•  Radiology:

•  CT•  MRI•  Bonescans–sensitivebutnotspecific•  Galliumscans–morespecific•  Imagingcannotdistinguishcancerfrominfection

Diagnostic Challenges

Highindexof

suspicion

Diabetesorother

immune

compromise?

Pseudomonas

aeruginosa

isolatedfromear

canal

Supportive

clinicalfeatures

Radiological

features

Treatment

•  LackofRCTstoguidetreatment•  50%mortalitypre1960s.20%aftersemi-syntheticpenicillins(Chandler1968)

• Ciprofloxacinrevolutionisedtreatment(WisemanandBalfour1994)

•  Treatmentlengthvaries–6-8weeksminimum• Ciprofloxacinremovesneedforradicalsurgery• Hyperbaricoxygen–noevidencetoshowefficacy(Davis,Gatesetal.1992)

Management Algorithm

LiftedfromRubinGrandisJ,BranstetterBFt,YuVL.Thechangingfaceofmalignant(necrotising)externalotitis:clinical,radiological,andanatomiccorrelations.TheLancetInfectiousdiseases.2004;4(1):34-9.

Suspicion

Diagnosis

Treat

Monitor

Follow-up

NUH OPAT experience

•  23patients-16male,7female•  76-meanage(range47-95)•  8weeks-meantimetodiagnosis(range2-24)• Co-morbidities:

•  78%Diabetes•  9%other-CKD,renaltransplant•  13%none

• August2013–October2016

NUH OPAT experience

1916

14

20

2

4

6

8

10

12

14

16

18

20

Otalgia Otorrhoea Headache CranialNervePalsy Other

ReportedSymptoms

NUH OPAT experience •  91%sampled–mostsuperficialswabs

•  70%tissuesentforhistology•  1/23fungalbiomarkers•  CRPmean52(range<5-156)•  52%normalCRPatdiagnosis•  91%CTatdiagnosis•  26%nofollow-upimaging•  30%serialimaging

0123456789

10

1stLineAntibioticRegimens

Meantreatmentlength9.4weeks(range4.4–31.6weeks)

NUH OPAT experience

•  61%sufferedadverseeffects

17%

6%

6%

18%29%

6%

6%6%

6%

AdverseEffects

CNSeffects

DerangedLFTs

DrugInducedFever

RenalImpairment

Rash

Anaphylaxis

C.difficile

Blooddyscrasia

Vomiting

NUH OPAT experience •  1yearmortality17%

•  1diedasaresultofMOE•  Remaining3diedfromco-morbidities

•  OPATOutcomes•  65% cured•  26% improved•  9% failed

•  Radiologicalimprovement•  Yes 41%•  No 47%•  Unclear 12%

NUH OPAT MOE Summary

• Complexinfectioninacomplexgroup• Challengesindiagnosisandmanagement

•  17%mortality•  Nostandardisedimagingprotocol•  Nostandardisedantimicrobialprotocol•  Highrateofadverseeventstoantibiotics