Merck Manual

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David M. Kaylie

, MS, MD, Duke University Medical Center

Reviewed/Revised Dec 2022
Topic Resources

Etiology of Otorrhea

Causes of ear discharge may originate from the ear canal, the middle ear, or the cranial vault. Certain causes tend to manifest acutely because of the severity of their symptoms or associated conditions. Others usually have a more indolent, chronic course but sometimes manifest acutely (see table ).

Overall, the most common causes are


Evaluation of Otorrhea


History of present illness in patients with ear discharge should cover duration of symptoms and whether symptoms have been recurrent. Important associated symptoms include pain, itching, decreased hearing, vertigo, and tinnitus. Patients are questioned about activities that can affect the canal or tympanic membrane (eg, swimming; insertion of objects, including cotton swabs; use of ear drops). Head trauma sufficient to cause a cerebrospinal fluid (CSF) leak is readily apparent.

Past medical history should note any previous known ear disorders, ear surgery (particularly tympanostomy tube placement), and diabetes or immunodeficiency.

Physical examination

Examination begins with a review of vital signs for fever.

Ear and surrounding tissues (particularly the area over the mastoid) are inspected for erythema and edema. The pinna is pulled and the tragus is pushed gently to see whether pain is worsened. The ear canal is inspected with an otoscope; the character of discharge and presence of canal lesions, granulation tissue, or foreign body are noted. Edema and discharge may block visualization of all but the distal canal (irrigation should not be used in case there is a tympanic membrane perforation), but when possible, the tympanic membrane is inspected for inflammation, perforation, distortion, and signs of cholesteatoma (eg, canal debris, polypoid mass from tympanic membrane).

When the ear canal is severely swollen at the meatus (eg, as with severe otitis externa) or there is copious drainage, careful suctioning can permit an adequate examination and also allow treatment (eg, application of drops, with or without a wick).

Red flags

The following findings are of particular concern:

  • Recent major head trauma

  • Any cranial nerve dysfunction (including sensorineural hearing loss)

  • Fever

  • Erythema of ear or periauricular tissue

  • Diabetes or immunodeficiency

Interpretation of findings


Many causes of ear discharge are clear after clinical evaluation.

If cerebrospinal fluid (CSF) leakage is in question, discharge can be tested for glucose or beta-2 transferrin; these substances are present in CSF but not in other types of discharge.

Patients without an obvious etiology on examination require audiogram and CT of the temporal bone or gadolinium-enhanced MRI. When auditory canal granulation is present, biopsy should be considered if clinical evaluation and CT are not clearly consistent with cholesteatoma.

Treatment of Otorrhea

Treatment is directed at the cause of the ear discharge. Most physicians do not treat a suspected CSF leak with antibiotics without a definitive diagnosis because drugs might mask the onset of meningitis. Sometimes a wick is placed to allow antibiotics to get into a very swollen ear canal (eg, with severe otitis externa).

Key Points

  • Acute discharge in a patient without chronic ear problems or immunodeficiency is likely the result of otitis externa or perforated otitis media.

  • Severe otitis externa may require specialty referral for more extensive cleaning and possible wick placement.

  • Patients with chronic or recurrent ear symptoms (diagnosed or undiagnosed), cranial nerve findings, or systemic symptoms should have specialty referral.

NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
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