Varicella Zoster Virus (Ramsay Hunt Syndrome)
The most likely causative organism in this patient with progressive deep ear pain, ear canal inflammation, and facial weakness (inability to move the left eye) is Varicella Zoster Virus (VZV), causing Ramsay Hunt syndrome (herpes zoster oticus).
Clinical Presentation Matches Ramsay Hunt Syndrome
The constellation of symptoms described—progressive deep tearing ear pain, ear canal inflammation, and facial nerve involvement (inability to move the left eye, suggesting facial weakness)—is pathognomonic for Ramsay Hunt syndrome 1.
- Characteristic features include: otalgia, pinna and/or ear canal vesicles (which may appear as "straw-colored" inflammation early), facial nerve paresis, and positive viral titers 1.
- The one-week progressive course is consistent with viral reactivation rather than acute bacterial otitis externa, which typically presents more acutely 2.
- Facial weakness with ear pain is a red flag for VZV infection rather than simple bacterial otitis externa 1.
Why Not Bacterial Otitis Externa
While bacterial otitis externa (primarily caused by Pseudomonas aeruginosa and Staphylococcus aureus) is the most common cause of ear canal inflammation, it does not cause facial nerve paralysis 3, 2.
- Bacterial otitis externa presents with rapid onset (<48 hours) of ear canal inflammation, otalgia, and tragal tenderness, but neurologic findings indicate extension beyond simple canal infection 4, 2.
- The presence of facial weakness (cranial nerve VII involvement) indicates this is not uncomplicated bacterial otitis externa 1.
Distinguishing Ramsay Hunt from Necrotizing Otitis Externa
Necrotizing (malignant) otitis externa, caused by Pseudomonas aeruginosa, can present with cranial neuropathies but typically occurs in elderly diabetic or immunocompromised patients 4, 5.
- Necrotizing otitis externa presents with severe otalgia, granulation tissue in the ear canal, and progressive cranial nerve involvement (often starting with CN VII, then CN IX-XII) 5.
- However, the "straw-colored" canal inflammation and one-week progressive course are more consistent with viral vesicles than the granulation tissue and severe necrosis seen in necrotizing otitis externa 4, 5.
- Without mention of diabetes, immunosuppression, or granulation tissue, VZV remains the most likely diagnosis 1.
Critical Diagnostic Features to Confirm
- Look for vesicles: Examine the pinna, external ear canal, and posterior auricular region for vesicular lesions, which may be subtle or already ruptured 1.
- Assess facial nerve function: Complete facial nerve examination (forehead wrinkling, eye closure, smile symmetry) to document the extent of paresis 1.
- Check for hearing loss: Ramsay Hunt syndrome can cause sensorineural hearing loss and vestibular symptoms 1.
- Consider viral testing: Positive viral titers or cultures can confirm VZV, though treatment should not be delayed for testing 1.
Management Implications
- Antiviral therapy: Immediate treatment with acyclovir or valacyclovir is essential to prevent permanent facial nerve damage 1.
- Corticosteroids: Addition of prednisone may improve facial nerve recovery outcomes 1.
- Pain management: Severe neuropathic pain requires appropriate analgesics, often including gabapentin or pregabalin 1.
- Ophthalmologic protection: If eye closure is incomplete, artificial tears and nighttime eye protection are critical to prevent corneal injury 1.
Common Pitfalls to Avoid
- Mistaking Ramsay Hunt for simple bacterial otitis externa and treating only with topical antibiotics, missing the window for antiviral therapy 1.
- Failing to examine for vesicles in the ear canal, pinna, and posterior auricular region, which may be subtle or already crusted 1.
- Delaying treatment while waiting for viral confirmation—treatment should begin immediately based on clinical presentation 1.
- Missing incomplete eye closure and failing to protect the cornea, risking exposure keratopathy 1.