Familial Bell's palsy in females: a phenotype with a predilection for eyelids and lacrimal gland.

The authors report a family with familial Bell's palsy affecting seven individuals, six of whom are females. This is a distinct subtype of Bell's palsy with a predilection for juvenile females, previously reported only very rarely. In conjunction with a review of the literature, this case suggests that this phenotype carries with it a greater risk of serious complications affecting the eyelids and lacrimal gland. These carry significant functional and cosmetic implications owing to aberrant regeneration of the seventh, sixth and possibly third cranial nerves, chronicity and relapses. Clinical features include synkinesis of the eyelids with the orbicularis oris causing synkinetic ptosis, recurrent paralytic ectropion, paralysis of facial muscles of expression with dry eye, hyperlacrimation (crocodile tears), and transient strabismus. Clinically, the decision to offer surgery in place of conservative treatment should consider the natural history of chronicity and relapses often seen with this subtype of familial Bell's palsy. Botulinum toxin injections are especially versatile in managing the complications associated with this phenotype.