A 16-year-old female presents with a 2-day history of sudden onset of right-sided facial weakness, making it difficult to close her eye, smile, or wrinkle her forehead. She denies headache, fever, or trauma. She reports a recent viral illness. On examination, the FNP notes complete paralysis of the right side of her face, including the forehead. All other neurological findings are normal. What is the most likely diagnosis?
- ABell's Palsy.
- BLyme disease.
- CHerpes zoster oticus (Ramsay Hunt syndrome).
- DStroke.
Show answer & explanationAnswer & explanation
Correct answer: A. Bell's Palsy.
The patient's presentation of acute, unilateral facial paralysis affecting the entire side of the face (including the forehead, indicating lower motor neuron involvement) without other neurological deficits, and often preceded by a viral illness, is classic for Bell's Palsy. This distinguishes it from a stroke, which typically spares the forehead (upper motor neuron lesion). While Ramsay Hunt and Lyme disease can cause facial palsy, they would have additional characteristic symptoms not present here.
Why the other options are wrong
- B. Lyme disease can cause facial palsy, but it is often bilateral, can be accompanied by other systemic symptoms (e.g., rash, arthralgia), and is less likely to be an isolated presentation in this scenario without other indicators.
- C. Herpes zoster oticus (Ramsay Hunt syndrome) would typically present with a painful vesicular rash in the ear canal or on the auricle, which is not mentioned.
- D. A stroke causing facial weakness typically spares the forehead (upper motor neuron lesion), unlike the patient's presentation of complete hemifacial paralysis.
Bell's Palsy
Bell's Palsy is an idiopathic, acute, unilateral peripheral facial nerve palsy (affecting cranial nerve VII) resulting in weakness or paralysis of the entire face on the affected side.
- Affects both upper and lower face (inability to wrinkle forehead).
- Often preceded by viral illness.
- Diagnosis of exclusion after ruling out other causes.
Memory trick: Bell's: Forehead Folds, No Other Faults