Guidance for primary care clinicians diagnosing and managing children with febrile seizure

According to the American Academy of Pediatrics, a febrile seizure is a seizure accompanied by fever (temperature ≥ 100.4°F or 38°C2 by any method), without central nervous system infection, that occurs in infants and children 6 through 60 months of age. [Subcommittee: 2011] Typical children have a 2-5% risk of febrile seizures. [Baumann: 2000]

Other Names

Characteristics of a simple febrile seizure [Subcommittee: 2011]

• The seizure occurs in a normally developing child without underlying neurologic problems, evidence of meningitis or encephalitis, or metabolic disturbances.
• The child is 6 months to 5 years of age.
• The fever is present before or with the seizure.
• The seizure is generalized, involving arms and legs.
• There is only 1 seizure in 24 hours.
• The seizure lasts less than 15 minutes.

Complex febrile seizures
Children with complex febrile seizures have a different prognosis and treatment than those with simple febrile seizures. If the seizure has any of the following features, it is a complex febrile seizure:

• Focal features
• Prolonged (greater than 15 minutes)
• Recurs within 24 hours of a first febrile seizure

Subcommittee on febrile seizures.
Neurodiagnostic evaluation of the child with a simple febrile seizure.
Pediatrics. 2011;127(2):389-94. PubMed abstract

In the clinical setting of a simple febrile seizure (i.e., a child with the appropriate history and normal exam), brain imaging, blood studies (CBC, electrolytes, calcium, phosphorus, magnesium, glucose), and EEG are not thought to be necessary for children over a year of age.

The American Academy of Pediatrics (AAP) recommends that a lumbar puncture be strongly considered in children:

• <12 months old
• With any sign of intracranial infection, such as neck stiffness or Kernig and Brudzinski signs
• That might have been pre-treated with antibiotics

The AAP also recommends that a lumbar puncture be considered in children from 12 to 18 months, as meningeal signs might be difficult to appreciate in this age group. [Subcommittee: 2011] The risk for meningitis in a child with a simple febrile seizure is low. [Guedj: 2015]

There is a 2-5% risk of febrile seizures in typical children. [Baumann: 2000]

The recurrence risk for future febrile seizures is 50% for children under 1 year, 30% for children over 1 year, and 50% for children who have experienced 2 febrile seizures (not given by age range).

Simple febrile seizures are generally benign and have a good prognosis; the child is unlikely to have developmental problems or future epilepsy. Treatment does not appear to improve long-term outcomes, and good outcomes are expected.

In more detail, the risk of epilepsy for all children with febrile seizures is 2-5%; this increases to about 10% when the child has 2-3 risk factors. Risk factors include age less than 12 months, multiple febrile seizures, a family history of epilepsy, a prior neurologic insult, or an abnormal baseline neurologic exam. [Mewasingh: 2020] [Lee: 2016]

R56.00, Simple febrile convulsions