Paediatrics: Bell’s palsy

Bell’s palsy

·Acute paralysis of the muscles of facial expression may be unable to close the eye on the affected side.

·Normally unilateral, but may be bilateral lower motor neuron lesion.

·2^o to oedema of the facial nerve as it passes through the temporal bone.

Aetiology

·Idiopathic.

·Varicella and other viruses.

·Borrelia burgdorferi (Lyme disease), particularly if bilateral.

Examination

·Check: whether other branches of the facial nerve are affected, e.g. hyperacusis.

·Full systemic examination: in particular, look for signs of leukaemia and vasculitides.

·Full neurological examination: look for other signs, the presence of which would exclude an idiopathic Bell’s palsy.

Investigation

·FBC and film (leukaemia).

·Varicella titres.

·Borrelia investigation, in suspicious cases, only after discussion with microbiology as this is a difficult infection to either refute or confirm.

Treatment

·Steroids: evidence for the use of steroids is limited, but the general opinion is to use 2mg/kg (maximum 60mg) prednisolone, once daily for 5 days if the symptoms are less than 7 days old.

·Aciclovir: recent evidence indicates that oral aciclovir (40mg/kg/day) for 10 days, irrespective of varicella status, may be useful.

Prognosis 

Most children will either recover fully or recover to a good degree. When this does not occur after 6mths, referral for facial nerve grafting is appropriate.