Is This a Simple Febrile Seizure?
Yes, this 18-month-old child with a 5-minute generalized seizure, now alert, and fever of 102°F meets all criteria for a simple febrile seizure and requires no neuroimaging, laboratory testing, or anticonvulsant prophylaxis. 1, 2
Diagnostic Criteria Met
This case fulfills all requirements for simple febrile seizure classification:
- Age appropriate: 18 months falls within the 6 months to 5 years age range 1
- Seizure duration: 5 minutes is well below the 15-minute threshold for complex classification 1, 2
- Generalized seizure: No focal features described 1, 2
- Single episode: No recurrence within 24 hours 1
- Fever present: Temperature of 102°F (38.9°C) exceeds the 100.4°F (38°C) threshold 1, 3
- Alert post-ictally: Return to baseline mental status excludes concerning pathology 2
What NOT to Do
Neuroimaging is explicitly NOT indicated for simple febrile seizures, even though 11.4% of children may have incidental brain abnormalities on MRI that do not affect clinical management or outcomes 1, 2
No laboratory testing is routinely required except as needed to identify the fever source 2, 3
No EEG is indicated - electroencephalography is explicitly listed as an inappropriate investigation for simple febrile seizures 2
No anticonvulsant prophylaxis should be prescribed - neither continuous nor intermittent therapy is recommended, as potential toxicities clearly outweigh minimal risks 2, 4
Critical Pitfall to Avoid
Do not confuse this with a complex febrile seizure. Complex febrile seizures require one or more of: duration ≥15 minutes, focal neurologic findings, or recurrence within 24 hours 1, 2. This case has none of these features.
Prognosis and Parent Counseling
Reassure parents that simple febrile seizures are benign with excellent long-term outcomes:
- No decline in IQ, academic performance, or neurocognitive function 2
- No structural brain damage 2
- Risk of developing epilepsy is approximately 1% by age 7 (identical to general population) 2
- Recurrence risk is approximately 30% for children older than 12 months at first seizure 2
When to Consider Further Evaluation
Lumbar puncture should be considered if meningitis is suspected based on clinical examination, particularly in children under 12 months where meningeal signs may be absent 2
Neurological consultation is warranted only if there are prolonged seizures, repetitive focal seizures, abnormal neurological examination, or developmental concerns 2