Eucalyptus Oil-Induced Seizures in Children: A Single-Center Prospective Study

Abstract

Objective Eucalyptus oil (EO) is known to have proconvulsant properties. EO is present in many over-the-counter preparations and used orally or topically to treat many ailments. In this study, we seek to describe clinical features, neuroimaging, and electroencephalographic findings and follow up outcome in children with eucalyptus oil-induced seizures (EOIS). Materials and methods This was a single-center prospective observational study, conducted at a tertiary care hospital from South India over a period of two years. Children (up to 18 years of age) with a first afebrile seizure or breakthrough seizures with preexisting epilepsy and with a recent exposure to EO were included. Data from all the children including demographic data, exposure to EO, mode of exposure, time to onset of seizures in relation to exposure, duration of seizure, type of seizure, investigations, and antiepileptic drug therapy were noted. All the patients were followed up for recurrence of seizures for six to nine months. Results During the study period of two years, a total of 17 children met the inclusion criteria, with a median (range) age of 3.75 years (23 - 150 months) and 10 (59%) were male. Only one patient had breakthrough seizures and all other 16 children had a first episode of seizure. All the children had generalized tonic-clonic seizures with median duration of three minutes (30 sec - 30 minutes). The median (range) interval between EO exposure and the onset of seizures was 20 minutes (10 - 120 minutes). All the children had taken EO drops orally mixed in either water or milk in different amounts. All the patients' brain neuroimaging was normal. All the patients had normal electroencephalography except for four children. Only five patients were treated with antiepileptic drugs for two weeks and one patient with preexisting epilepsy was continued on the same antiepileptic drug. None of the patients had a recurrence of seizures during the follow-up period of six to nine months. Conclusion EOIS is an underrecognized and rare entity of seizures in children. EOIS can occur as first seizures or as breakthrough seizures in preexisting epilepsy patients. Despite the previous case reports in the literature quoting the seizurogenic potential of EO, this awareness is lacking in both clinicians and parents. We also recommend clinicians inquire about exposure to EO while approaching a child with first afebrile seizures or breakthrough seizures, which can prevent unnecessary investigations and long-term antiepileptic drug therapy.

Keywords: electroencephalography; eucalyptus oil; first seizures; ingestion; neuroimaging.