INFECTIONS OF THE EXTERNAL EAR
EMBRYOLOGY     -AURICLE – 6 HILLOCKS FROM 1ST AND 2ND ARCHES—1ST ARCH—–TRAGUS, HELICAL ROOT, AND HELIX—2ND ARCH–ANTI-HELIX, ANTI-TRAGUS, AND LOBULE
-EAC – 1ST BRANCHIAL CLEFT FORMS EAC AND CONTACTS 1ST BRANCHIAL POUCH TO FORM TYMPANIC  MEMBRANE; CANALIZATION COMPLETE AT 12 WEEKS AND EPITHELIAL PLUG REMAINS UNTIL 28TH WEEK
PREDISPOSING     -EXCESSIVE CLEANING OF EAC CAUSING DAMAGE TO CERUMEN COAT AND APOPILOSEBACEOUS UNIT-ANATOMIC ABNORMALITY NOT ALLOWING APPROPRIATE FXN OF APOPILOSEBACEOUS UNIT—-DIABETES MELLITUS OR OTHER IMMUNOSUPPRESSIVE/DEFICIENT STATE
PATHOGENS—-PSEUDOMONAS MOST COMMON, BUT MAY BE PROTEUS, STAPH, STREP, AND OTHER G- ORGANISMS
MALIGNANT/ NOE    -AGGRESSIVE INFECTION THAT CAN SPREAD THROUGHOUT T-BONE AND EXTEND TO SKULL BASE ULTIMATELY LEADING TO CRANIAL NEUROPATHIES AND DEATH
-USUALLY SEEN IN ELDERLY DIABETIC OR DEBILITATED PATIENTS OR IN THOSE WITH IMMUNOSUPPRESSION /DEFICIENCIES
-USUALLY STARTS AS ACUTE OE AND DOES NOT GET OR RESPOND TO THERAPY; SPREADS THROUGH FISSURES OF SANTORINI
-DX
1. OTALGIA FOR GREATER THAN A MONTH, USUALLY DEEP SEATED
2. PERSISTENT FETID PURULENT OTORRHEA WITH GRANULATION TISSUE PRESENT
3. DIABETES, IMMUNOSUPPRESSION/DEFICIENCY
4. CRANIAL NERVE INVOLVEMENT
-PE – SWOLLEN, ERYTHEMATOUS EAC FULL OF PURULENT DRAINAGE AND GRANULATION TISSUE USUALLY ALONG THE FLOOR; SURROUNDING SOFT TISSUE INFECTION AND POSSIBLE NEUROLOGICAL DEFICITS
-PATHOGENS – PSEUDOMONAS MOST COMMON, BUT MAY BE PROTEUS, STAPH, KLEBSIELLA, OR ASPERGILLUS
-CRANIAL NERVE – CN 7 -75%, CN 10 – 70%, CN 11 – 50%
-RADIOGRAPHY – CT SCAN CAN SHOW BONY CHANGES AND SOME SOFT TISSUES CHANGES, MRI CAN BETTER DELINEATE SOFT TISSUE CHANGES, AND MRA CAN DETERMINE PATENCY OF GREAT VESSELS AND DURAL SINUSES
-RADIONUCLIDE – TECHNETIUM 99M -INDICATES THE BONY CHANGES WHICH CAN BE RELATED TO OSTEOMYELITIS OR ANY OTHER BONY REMODELING PROCESS WHILE THE GALLIUM 67 SCAN  INDICATE S AREAS OF INFECTION BY DETERMINING PRESENCE OF PMNS; NEED TO FOLLOW GALLIUM  EVERY  6 WEEKS TO MONITOR THERAPY

-TREATMENT – IV ABX FOR AT LEAST 6 WEEKS WITH CULTURES HELPING TO DIRECT CHOICE ( USUALLY DOUBLE COVERAGE FOR PSEUDOMONAS); SOME MAY TREAT WITH ORAL CIPRO BUT MUST TREAT FOR AT LEAST 6 MONTHS
– METICULOUS EAR CLEANING
– ABX  DROPS
– STRICT CONTROL OF DIABETES IF PRESENT
– ? ROLE FOR HYPERBARIC OXYGEN
– SURGERY IS RESERVED FOR THOSE NOT RESPONDING TO MEDICAL THERAPY AND ARE SHOWING PROGRESSION OF PAIN, DRAINAGE, GRANULATION TISSUE, OR CRANIAL  NEUROPATHIES; NEED WIDE DEBRIDEMENT +/- MASTOIDECTOMY, FACIAL NERVE  DECOMPRESSION, OR T-BONE RESECTION
-PAIN USUALLY SUBSIDES WITH SUCCESSFUL TREATMENT BUT MUST FINISH FULL ABX               COURSE
-COMPLICATIONS – MENINGITIS, BRAIN ABSCESS, DEATH
-23% MORTALITY FOR ALL PATIENTS
-60% MORTALITY IF PT HAS CRANIAL NEUROPATHIES
BULLOS OE—PAINFUL, SOMETIMES HEMORRHAGIC BULLA OF THE BONY EAC WHICH MAY BE CAUSED BY PSEUDOMONAS
TX – ABX DROPS, DO NOT RUPTURE VESICLES SINCE CAN LEAD TO SECONDARY INFECTION
GRANULAR OE—-SMALL AREAS OF GRANULATION TISSUE IN EAC BUT NOT AS SEVERE AS NOE; PTS NOT DIABETIC OR  IMMUNOSUPRESSED
-TX – REMOVE GRANULATION TISSUE, CAUTERIZE AREA, AND ABX DROPS; WILL NEED ORAL ABX IF EXTENSIVE SOFT TISSUE INVOLVEMENT

OTOMYCOSIS    -USUALLY A SUPERINFECTION OF CHRONIC BACTERIAL INFECTION OR MAY BE SEEN IN MASTOID  BOWLS OF HEARING AID USERS
-USUALLY ASPERGILLUS
-PRESENTS AS PRURITUS
-TX  – CLEAN, DOMEBORO’S OR OTHER DRYING SOLUTION, TOPICAL ANTIFUNGAL