What are the potential causes of ear bleeding in a patient with a normal Magnetic Resonance Imaging (MRI) scan and normal coagulation profile?

Causes of Ear Bleeding with Normal MRI and Coagulation Profile

In a 36-year-old female with ear bleeding, normal MRI, and normal coagulation studies, the most likely causes are local ear pathology including auricular hematoma from unrecognized minor trauma, hemotympanum from barotrauma or upper respiratory infection, or chronic serous otitis media with bloody effusion. 1, 2

Primary Local Ear Causes

Auricular Hematoma

• Auricular hematoma results from shearing or blunt trauma to the ear, causing blood accumulation in the subperichondrial space, and can occur even without recalled trauma. 1
• The patient may not remember minor trauma that occurred days prior, as evacuation is indicated within 7 days of injury. 1
• Physical examination reveals a fluctuant hematoma within the cartilaginous auricle. 1

Hemotympanum (Blood Behind Eardrum)

• Hemotympanum can develop from increased middle ear pressure during coughing or sneezing, particularly in the setting of upper respiratory infection, even without trauma. 3
• Otoscopic examination shows a blue or dark discoloration of the tympanic membrane due to blood in the middle ear space. 2
• This condition can occur spontaneously with viral upper respiratory infections causing sudden pressure changes. 3

Chronic Serous Otitis Media with Bloody Effusion

• The "blue ear drum" represents chronic serous otitis media accompanied by bloody effusion, which can occur without identifiable trauma or coagulopathy. 2
• This condition presents with hypocellular mastoid, hyperplastic mucoperiosteal lining, and cholesterin granuloma on imaging if chronic. 2
• Initial management is conservative with medical therapy and possible myringotomy with ventilation tubes. 2

Less Common but Important Causes

Barotrauma

• Sudden pressure changes from flying, diving, or forceful Valsalva maneuvers can cause middle ear hemorrhage. 4
• The normal MRI excludes temporal bone fracture, which would be visible on CT but not necessarily on standard MRI sequences. 4

Vascular Lesions (Excluded by Normal MRI)

• While the normal MRI makes vascular malformations unlikely, CT angiography would be more sensitive than standard MRI for detecting small vascular anomalies in the temporal bone. 4
• Aneurysms of vessels within the temporal bone have been reported but would typically show on contrast-enhanced imaging. 5

Critical Diagnostic Pitfall

The key pitfall is that standard brain MRI may not adequately visualize the temporal bone structures, external auditory canal, or middle ear pathology that causes ear bleeding. 4

• High-resolution CT of the temporal bone (not routine head CT) is the preferred imaging modality for evaluating ear bleeding when MRI is normal. 4
• Standard MRI protocols focus on brain parenchyma and may miss subtle temporal bone or middle ear pathology. 4

Recommended Diagnostic Approach

Immediate Physical Examination

• Perform otoscopic examination to identify auricular hematoma, hemotympanum (blue eardrum), or external auditory canal lesions. 1, 2
• Examine for petechiae, ecchymosis, or wet purpura elsewhere that might suggest occult platelet dysfunction despite normal initial coagulation studies. 3

Additional Testing if Initial Exam Non-Diagnostic

• Consider high-resolution CT temporal bone (not standard head CT) if otoscopy is unrevealing, as this is superior to MRI for temporal bone pathology. 4
• Obtain complete blood count with platelet count, as thrombocytopenia can cause hemotympanum even with normal PT/PTT/INR. 3
• Consider von Willebrand factor studies or platelet function testing if bleeding persists, as these are not part of routine coagulation profiles. 3

History Details to Elicit

• Recent upper respiratory infection symptoms, as viral infections can precipitate hemotympanum through pressure changes. 3
• Any history of forceful nose blowing, sneezing, coughing, or Valsalva maneuvers. 3
• Unrecognized minor ear trauma from sports, sleeping position, or ear manipulation. 1
• Previous episodes of ear fullness or hearing changes suggesting chronic ear disease. 2

Management Based on Findings

If auricular hematoma is identified, evacuation via needle aspiration or incision and drainage with bolster dressing is indicated within 7 days, followed by fluoroquinolone antibiotics for 7-10 days. 1

If hemotympanum is present, conservative management with observation and prophylactic antibiotics (amoxicillin-clavulanate) is appropriate, with follow-up in 2 weeks. 3, 2

If chronic serous otitis with bloody effusion is diagnosed, initial medical therapy followed by myringotomy with ventilation tubes if conservative measures fail. 2