How is it Diagnosed?
Febrile seizures are diagnosed clinically, primarily in children between 6 months and 5
years of age who experience a seizure in association with fever (≥100.4°F or 38°C)
without evidence of intracranial infection or defined neurological pathology.
The clinician begins with a detailed history from the caregiver, including the age of the
child, duration and type of seizure (generalized or focal), presence of fever, and any
previous seizure episodes. Simple febrile seizures are generalized, last less than 15
minutes, and do not recur within 24 hours. Complex febrile seizures may be focal, last
longer, or recur during the same illness.
A complete physical and neurological examination follows. Signs of meningeal irritation
(e.g., neck stiffness, photophobia) or altered consciousness beyond the postictal period
raise concern for meningitis or encephalitis.
Laboratory investigations like CBC, CRP, and blood cultures are done if bacterial
infection is suspected. Urinalysis is common in infants to identify urinary tract
infections. In children under 12 months or with atypical symptoms, lumbar puncture may
be required to rule out meningitis.
Electroencephalogram (EEG) and neuroimaging (CT or MRI) are not routinely needed for
simple febrile seizures but may be considered in complex or recurrent cases.
The diagnosis is made after excluding other causes of seizures and confirming the
association with fever in a previously healthy child. Prognosis is generally excellent for
simple febrile seizures.