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The information – Bell’s palsy

The patient’s unmet needs (PUNs)

A 20-year-old woman who is otherwise well and on no medication, presents with a two-day history of weakness on the left side of her face. She has self-diagnosed Bell’s palsy – which you confirm on examination. Her eye on the affected side is sore, though vision is normal. She has discovered that some doctors advise aciclovir because the palsy may be caused by Herpes simplex virus. She wants to know your view – and whether she should have a course of steroids.

The doctor’s educational needs (DENs)

How common is Bell’s palsy and what are the current theories of causation?

Bell’s palsy – a partial or complete idiopathic lower motor neurone facial paralysis – has an incidence of between

11 and 40 per 100,000 per year. Around two-thirds of cases of acute facial weakness are truly idiopathic. The peak incidence is between 30 and 50 years of age, with an equal male-to-female ratio.

The aetiology is unclear, but an infectious origin is most likely, triggering an immunological response which leads to neuronal injury. HSV has been implicated, but HSV type 1 can be isolated from 86% of human geniculate ganglion cells with no history of facial palsy.

How can the GP confidently exclude other causes for this type of symptom?

The classical Bell’s palsy history is of a short duration. Patients report pain on the affected side, which may be post-auricular. Subsequently, they develop weakness that peaks within

48 hours. Slower onset, or progressive weakness, suggests a more sinister cause.

Clinical examination should confirm the lower motor neurone weakness. The ears and neck, including the parotid gland and facial skin, should be carefully examined. An assessment of the patient’s eye closure is mandatory. Finish with a full cranial nerve examination. If this reveals no other abnormalities, the diagnosis is very likely to be Bell’s palsy.

What treatment should be offered? How time-sensitive are these treatments?

Patients with clear or suspected Bell’s palsy should be started on oral corticosteroids as soon as possible after onset, ideally within 72 hours. This treatment improves outcomes, but there is no additional benefit from antiviral regimens, according to a trial that compared antivirals with corticosteriods, and we would not recommend them1. The treatment arm of the study used prednisolone as a single 25mg tablet, taken twice daily for 10 days. There is no evidence of benefit of steroids initiated later than 72 hours, but we would consider trying them up to two weeks. 

Antiviral medication is mandated in Ramsay-Hunt syndrome – suggested by vesicles around the pinna or in the mouth, on the tongue or on the palate.

What potential ocular complications are there? How can GPs prevent or treat them?

Patients with severe weakness and incomplete eye closure may experience corneal exposure, leading to drying and trauma, and irreversible ulceration can occur.  So, in addition to pharmacological treatment, eye care with lubrication is appropriate – taping at night and daytime eye protection are advised.

What is the prognosis of Bell’s palsy, and do certain patient groups have a worse outlook than others? What are the possible long-term complications?

Most patients with Bell’s palsy will recover well, but up to 30% will have a poor outcome with persistent facial weakness and associated psychological distress. One study showed 72% of those treated with prednislone returned to normal movement at 12 months. Those who do not receive steriods can expect a resolution rate of less than 60%. 

Sometimes reinnervation of the target muscles occurs in a haphazard way, and synkinesis – the involuntary movement of one part of the face while attempting to move another, for example the mouth moving on tight eye closure – may result.

Pregnancy appears to protect women from Bell’s palsy, although pregnant women who are affected seem to have a worse prognosis. Poor prognosis is also associated with complete paralysis, slow recovery and older age. Idiopathic facial palsy is recurrent in up to 15% of cases. Care should be taken to exclude a middle ear or skull base cause. Referral is recommended for any patient where clinical examination suggests another cause, those with incomplete recovery and when the palsy is recurrent.


Mr Christopher Skilbeck is an ENT/skull base fellow and Mr Rupert Obholzer is a consultant ENT/skull base surgeon at Guy’s & St Thomas’ Hospitals, London

This article was produced with Facial Palsy UK – a new charity dedicated to providing information and supporting patients and their families. Click on the link for more information.



1 Sullivan FM, Swan IRC, Donnan PT et al. Early treatment with prednsiolone or aciclovir in Bell’s palsy. N Engl J Med 2007; 357:1598-1607

Further reading

  • Davenport RJ, McKinstry B, Morrison JM et al. Bell’s palsy: new evidence provides a definitive drug therapy strategy. Br J Gen Pract 2009;59:569-70
  • Salinas RA, Alvarez G, Daly F and Ferreira J. Corticosteroids for Bell’s palsy (idiopathic facial paralysis). Cochrane Database of Systematic Reviews. 2010
  • Lockhart P, Daly F, Pitkethly M et al. Antiviral treatment for Bell’s palsy (idiopathic facial paralysis). Cochrane Database of Systematic Reviews. 2009