differential diagnosis
Last reviewed 04/2023
- Bell's palsy must be distinguished from other causes of facial palsy - see facial palsy for more information
- the differential diagnosis includes:
- nuclear (peripheral) causes (1)
- lyme disease
- this is more likely if the facial weakness is bilateral
- history of tick exposure, and arthralgias
- look for a rash
- otitis media
- suppurative otitis is excluded by examining the ear
- there is gradual onset ear pain, fever, and conductive hearing loss
- Ramsay Hunt syndrome
- herpes zoster may produce an acute facial weakness but is accompanied by a rash within the auricle - geniculate herpes - or on the palate, pharynx, face, neck or trunk
- there may be a pronounced prodrome of pain
- sarcoidosis
- sarcoidosis affecting the parotid gland is suggested by recurrent facial palsy
- facial weekness is often bilateral
- Guillain-Barré
syndrome
- facial weekness is often bilateral
- HIV infection
- more likely if the facial weakness is bilateral
- look for lymphadenopathy
- tumours
- cholesteatoma, parotid gland tumours
- lyme disease
- supranuclear
(central) causes (2)
- multiple sclerosis
- multiple sclerosis should be considered if the palsy is unilateral, in a young adult, is painless, and resolves in 2-3 weeks
- stroke
- tumours
- metastases or primary brain tumours
- history of cancer
- look for mental status changes
- multiple sclerosis
- nuclear (peripheral) causes (1)
- Horner's syndrome and IIIrd nerve palsies produce a ptosis
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