Recurrent 6(th) nerve palsy in a child following different live attenuated vaccines: case report

BACKGROUND: Recurrent benign 6(th) nerve palsy in the paediatric age group is uncommon, but has been described following viral and bacterial infections. It has also been temporally associated with immunization, but has not been previously described following two different live attenuated vaccines. CASE PRESENTATION: A case is presented of a 12 month old Caucasian boy with recurrent benign 6(th) nerve palsy following measles-mumps-rubella and varicella vaccines, given on separate occasions with complete recovery following each episode. No alternate underlying etiology was identified despite extensive investigations and review. CONCLUSIONS: The majority of benign 6th nerve palsies do not have a sinister cause and have an excellent prognosis, with recovery expected in most cases. The exact pathophysiology is unknown, although hypotheses including autoimmune mechanisms and direct viral invasion could explain the pathophysiology behind immunization related nerve palsies. It is important to rule out other aetiologies with thorough history, physical examination and investigations. There is limited information in the literature regarding the safety of a repeat dose of a live vaccine in this setting. Future immunizations should be considered on a case-by-case basis.