F Letter

पृष्ठभूमि

A febrile seizure is a fit or convulsion that is typically caused by a sudden rise in a child’s body temperature, usually occurring in the context of a fever. Among healthy children, 3% will have a febrile seizure in their lifetime. Febrile seizures most commonly occur between the ages of 6 months and 6 years. Febrile seizures can be classified as either simple or complex. 

Simple febrile seizures feature fever and सभी of the following: 

• generalised tonic-clonic seizure (involving muscle stiffening and twitching/jerking)
• duration of less than 15 minutes 
• complete recovery within 1 hour
• no recurrence within the same febrile illness. 

Complex febrile seizures feature fever and any of the following: 

• focal features at onset or during the seizure (e.g. staring, eye deviation, face or limb twitching)
• duration of more than 15 minutes
• recovery not complete after 1 hour
• recurrence within the same febrile illness. 

Although febrile seizures can be alarming to witness, they are not harmful. Children who have a febrile seizure, and do not have other risk factors for epilepsy, are not at an increased risk of developing epilepsy compared to the rest of the population. 

Febrile seizures and vaccines

Fever is a common side effect following vaccination with certain vaccines (e.g. meningococcal B, COVID-19, MMR, MMRV और

). Fever generally occurs within 48 hours of inactivated vaccines and 5 to 10 days after the administration of live-attenuated vaccines. Although vaccines can cause fevers, febrile seizures are not common after vaccination. It is important to note that fever is a common symptom of many vaccine-preventable diseases. 

Febrile seizures that occur within 14 days of vaccination are called vaccine-proximate febrile seizures (i.e. they are temporally associated with vaccination). Vaccine-proximate febrile seizures are not more severe than febrile seizures that are not temporally associated with vaccines. Whether a febrile seizure is vaccine proximate or not has no bearing on the outcomes following the seizure. 

Vaccine-proximate status epilepticus, vaccine-proximate afebrile seizures, and epilepsy

Status epilepticus is a prolonged seizure or multiple seizures without recover of consciousness between each seizure. Afebrile seizures are seizures occurring in the absence of fever. 

Vaccine-proximate status epilepticus and vaccine-proximate afebrile seizures are very rare. 

Some children with specific types of epilepsy, including Dravet syndrome or genetic epilepsy with febrile seizures (GEFS+), may present in the first instance with a vaccine-proximate seizure. Refer to MVEC: Epilepsy अधिक जानकारी के लिए।

Recommendations

Vaccine setting

Children with a history of simple vaccine-proximate febrile seizures or seizures from another cause can be safely vaccinated in the community without the need for additional monitoring.  

Children who have experienced a complex vaccine-proximate febrile seizure, vaccine-proximate status epilepticus or vaccine-proximate afebrile seizures should be referred to a specialist immunisation clinic for further assessment before receiving further vaccinations. These seizures should be reported to the adverse event reporting service in your jurisdiction. In Victoria, this is सैफविक. 

If parents are concerned about the safety of vaccination or if providers wish to defer advice to a specialist, referral to a specialist immunisation clinic can be considered for any child with a history of seizures.

Prophylactic paracetamol

It is widely recognised that children receiving Bexsero (meningococcal B vaccine) are more likely to experience fevers following vaccination. MVEC recommends children under 4 years receive prophylactic paracetamol (15 mg/kg per dose) prior to vaccination, as well as 2 subsequent doses (6 hours apart) to reduce the likelihood and severity of fever. This should be administered regardless of whether the child is experiencing a fever.

The administration of prophylactic paracetamol prior to other vaccines is not routinely recommended.

एहतियात

Measles-mumps-rubella-varicella (MMRV) vaccines are not recommended as a first dose of a measles-mumps-rubella (MMR)-containing vaccine in children under 4 years due to the increased risk of fever (and possible febrile seizures).

Should MMRV vaccines be inadvertently administered as the first dose of an MMR-containing vaccine, the child’s parent should be counselled to monitor for fevers and administer paracetamol as required. This vaccine administration error should be reported to your jurisdiction’s adverse event reporting service.

संसाधन

• CDC: Febrile seizures और vaccines
• Epilepsy Foundation: Febrile seizures
• RCH Clinical Practice Guidelines: Febrile seizure
• RCH Kids Health Info: Febrile seizures
• Deng L, Wood N, Danchin M. Seizures following vaccination in children: Risks, outcomes and management of एसubsequent revaccination. Aust J Gen Pract. 2020;49(10):644-649. doi:10.31128/AJGP-02-20-5236
• Deng L, Gidding H, Macartney K, et al. Postvaccination febrile seizure severity and outcome. Pediatrics. 2019;143(5): doi:10.1542/peds.2018-2120