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Pathophys and Cause ⬇

Cause:

Bacterial: Staph, pseudomonas

Fungal: Aspergillus niger

Viral: Herpes simplex and zoster

Pathophys:

Bacterial: Local furunculosis, which then becomes more diffuse

Epidemiology ⬆ ⬇

Bacterial: Most common type of otitis externa

Signs and Symptoms ⬆ ⬇

Sx:

Allergic: 1+ pain; 3+ itching

Seborrheic: 1+ pain; 1+ itching

Bacterial: 3+ pain, esp w movement of pinna

Fungal: 1+ pain; 3+ itching

Viral: 1+ pain w herpes simplex; 3+ pain w herpes zoster

Si:

Bacterial: pain w tragal pressure and pinna traction; erythema and edema of external ear canal

Allergic: Acute: weeping small vesicles. Chronic: fissures and scales

Seborrheic: Greasy scales, dandruff

Fungal: Looks like wet newspaper; black discharge is diagnostic

Viral: Vessels in ear may rupture, or form hemorrhagic bullae

Complications ⬆ ⬇

Bacterial: malignant otitis externa, a severe perichondritis, now only a problem in pts w resistant organisms or diminished resistance, eg, diabetes, cancer, or AIDS

r/o: acute mastoiditis

Lab and Xray ⬆ ⬇

Lab: Bact:culture if drainage

Treatment ⬆

Rx:

Avoid water in all types

  • Allergic: Antihistamines; topical steroids
  • Seborrheic: Keep hair away from ears; topical steroids
  • Bacterial/fungal: Clean out well
  • Domeboro's soln, or 9:1 alcohol/vinegar soln gtts, to acidify area, which prevents pseudomonas growth, w wick (eg, "Pope's otowick," a commercial sponge material) if necessary to get into canal
  • Topical antibiotics and steroids (Cortisporin or Cipro HC) gtts tid-qid, or ofloxacin (Floxin) gtts bid
  • Glycerine to decrease swelling by hydroscopic action (VoSol)
  • Systemic antibiotics, eg, penicillin, dicloxacillin, cephalothin, or ciprofloxacin esp if P. aeruginosa(Nejm 1991;324:392) and if sensitive; malignant external OM, rx w ceftazidime (Rv Inf Dis 1990;12:173)
  • Viral: Sedation; occasionally local antibiotics; ? acyclovir