Febrile Seizure Clinical Overview
I. The "On-Call" Snapshot
Clinical Significance in Malaysia: This is one of the most common reasons for acute paediatric admission, especially in the under-5 age group. Your job is to rule out sinister causes like meningitis and provide reassurance.
High-Yield Definition: A seizure occurring in childhood after 6 months of age, associated with a febrile illness not caused by an infection of the central nervous system (CNS), without previous neonatal seizures or a previous unprovoked seizure, and not meeting criteria for other acute symptomatic seizures. (Adapted from Paediatric Protocols for Malaysian Hospitals, 4th Ed.)
Clinical One-Liner: Basically, it's a fit caused by a rapidly rising fever in a young child whose brain is otherwise healthy.
II. Etiology & Risk Factors
Etiology: The seizure is triggered by a rapid rise in core body temperature, typically >38.0°C. The fever is most commonly caused by a benign viral infection (e.g., URTI, Roseola Infantum) and less commonly, a bacterial source (e.g., UTI, otitis media).
Risk Factors:
Age: Peak incidence is between 12-18 months. (Commonly 6 months to 5 years).
Family History: A positive first-degree relative history of febrile seizures is a strong predictor.
Developmental Delay: Pre-existing neurological issues increase the risk.
High Fever: The rapidity of the temperature rise is more important than the peak temperature.
III. Quick Pathophysiology
Think of it this way: a child's brain is still developing its "wiring." A rapid change in temperature, which is a significant physiological stressor, can temporarily destabilize neuronal membranes. This leads to excessive, synchronous electrical firing, which manifests as a seizure. It's a transient functional disturbance, not a permanent structural problem.
IV. Clinical Assessment
Red Flags & Immediate Actions:
Seizure > 5 minutes (Status Epilepticus): Alert senior immediately. Start the seizure management protocol (ABCDE, check glucose, administer IV/buccal benzodiazepine).
Signs of Meningitis (Stiff neck, bulging fontanelle, photophobia): Alert senior. Prep for a lumbar puncture. This is no longer a simple febrile seizure; it's a CNS infection until proven otherwise.
Post-ictal drowsiness > 1 hour or focal neurological deficit: Alert senior. This suggests a complex seizure or an underlying brain pathology. Needs further investigation.
Age < 6 months: High index of suspicion for CNS infection. Discuss with your senior for LP.
History:
Common (>50%): Generalised tonic-clonic movements, brief duration (<5 minutes), post-ictal drowsiness that resolves within an hour. History of preceding URTI symptoms (cough, coryza).
Less Common (10-50%): Focal seizure features (one-sided shaking), duration up to 15 minutes.
Pertinent Negatives: No history of previous afebrile seizures, no recent head trauma, no known neurological problems.
Physical Examination:
Vital Signs: Focus on the temperature and haemodynamic stability.
Neurological Exam: Assess GCS, pupil response, tone, and power. Look for neck stiffness and check Kernig's/Brudzinski's signs in older children. Check the fontanelle in infants. The neurological exam should be normal after the post-ictal period.
Source of Fever: Perform a thorough examination to find the cause of the fever. Check the throat (tonsillitis), ears (otitis media), and lungs (pneumonia). Don't forget to look for a rash (e.g., Roseola).
Clinical Pearl: The seizure has usually stopped by the time the child arrives in the ED. Your main job is not to stop the fit, but to find the cause of the fever and rule out CNS infection. Document the duration and type of seizure based on the parents' account.
V. Diagnostic Workflow
Differential Diagnosis:
Meningitis/Encephalitis:
Points For: Fever, seizure, may have prolonged post-ictal state, irritability, or signs of meningism.
Points Against: Child is well-looking, interactive, and has a normal neurological exam after being post-ictal.
How to Differentiate: Lumbar Puncture is the gold standard. Have a low threshold in infants <12 months, especially if vaccination status is incomplete.
Underlying Epilepsy triggered by fever:
Points For: Atypical seizure features, previous afebrile seizures, strong family history of epilepsy.
Points Against: First-ever seizure, classic simple febrile seizure presentation, normal development.
How to Differentiate: EEG and further neurological workup as an outpatient, not usually done in the acute setting for a first simple febrile seizure.
Investigations Plan:
Bedside / Initial (First 15 Mins):
Blood Glucose: Mandatory. Hypoglycaemia can cause seizures.
First-Line Labs & Imaging (Only if indicated):
FBC, RP, LFTs: Generally not needed for a simple febrile seizure if the child is well and the source of fever is clear. Consider if the child appears septic or has other systemic symptoms.
Urine FEME/Culture: Consider in infants and young children without a clear source of fever.
Lumbar Puncture (LP):
Strongly Consider: Any child with meningeal signs, age < 12 months (especially < 6 months), or if the child has received antibiotics which may mask meningitis.
Discuss with your senior. It is an invasive procedure.
EEG/Neuroimaging (CT/MRI): NOT indicated for a first simple febrile seizure. Consider only for complex seizures (prolonged, focal) or if there are abnormal neurological findings.
VI. Staging & Severity Assessment
Classification is key as it dictates your management plan. This is based on the Paediatric Protocols for Malaysian Hospitals, 4th Ed.
Simple Febrile Seizure (Accounts for ~70-80%):
Generalised tonic-clonic seizure.
Lasts < 15 minutes.
Occurs only once in a 24-hour period during the same febrile illness.
Child is neurologically normal before and after the event.
Impact: Usually benign. Can be discharged from ED after a period of observation if the child is well and parents are comfortable.
Complex Febrile Seizure (Requires admission):
Has any of the following features:
Focal features (e.g., limited to one limb or side of the body).
Prolonged duration (≥ 15 minutes).
Multiple seizures occurring within 24 hours.
Impact: Higher risk of underlying abnormalities and a slightly higher risk of future epilepsy. Requires admission and further evaluation.
VII. Management Plan
Immediate Stabilisation (The ABCDE Plan - for a child still seizing):
Airway: Position the child in the lateral position. Use airway adjuncts if needed.
Breathing: Administer high-flow oxygen via face mask.
Circulation: Secure IV access.
Disability: Check blood glucose. If seizing > 5 minutes, give IV Diazepam 0.3-0.5mg/kg (max 10mg) or Buccal Midazolam 0.3-0.5mg/kg (max 10mg).
Exposure: Remove excess clothing to help cool the child. Treat the fever with Paracetamol 15mg/kg.
Definitive Treatment (The Ward Round Plan):
Simple Febrile Seizure:
Identify and treat the underlying cause of the fever.
Antipyretics (Paracetamol) for comfort. Counsel parents that antipyretics do not prevent febrile seizures.
Observe for a few hours in the ED. If the child returns to baseline, the source of fever is not serious, and parents are well-counselled, they can be discharged.
Complex Febrile Seizure:
Admit to the ward for observation.
Investigate further as clinically indicated (e.g., LP, neuroimaging after discussion with senior).
Prophylactic anticonvulsants are generally not recommended.
Long-Term & Discharge Plan:
Parental Education is crucial. This is your most important job.
Explain what a febrile seizure is and that it is generally benign.
Reassure them that it does not cause brain damage.
Provide first aid advice for managing a future seizure (place in recovery position, do not put anything in the mouth, time the seizure).
Provide a clear plan on when to return to the hospital (if seizure > 5 minutes).
Give them a written leaflet.
VIII. Complications
Immediate:
Febrile Status Epilepticus: Management requires escalation as per seizure protocol.
Physical Injury: Trauma during the seizure (rare).
Short-Term:
Recurrence: The biggest "complication." About 30-40% will have another febrile seizure. Risk is higher if the first seizure was at a younger age (<18 months) or there is a strong family history.
Long-Term:
Epilepsy: The risk of developing epilepsy is slightly higher than the general population (~2-5% vs 1%). The risk increases if the seizure was complex, there is a family history of epilepsy, or the child has a pre-existing neurodevelopmental abnormality.
IX. Prognosis
Excellent. The vast majority of children with simple febrile seizures have normal development and intelligence. The main prognostic factors for recurrence or developing epilepsy are:
Pre-existing neurodevelopmental abnormality.
Family history of epilepsy.
Complex febrile seizure features.
X. How to Present to Your Senior
"Dr., for your information/review. This is [Child's Name], a [Age]-year-old [boy/girl] in ED, who presented with a first episode of seizure with fever. The seizure was generalised, lasted approximately 3 minutes, and self-terminated. The child is now post-ictal but improving. On examination, vitals are stable except for a temperature of 39°C. There are no meningeal signs, and the ENT examination shows injected tonsils. My diagnosis is a first simple febrile seizure secondary to acute tonsillitis. I plan to observe for a few hours, give paracetamol, and counsel the parents for discharge if the child returns to baseline. I do not think a lumbar puncture is indicated at this time."
XI. Summary & Further Reading
Top 3 Takeaways:
Your primary role is to rule out CNS infection, not to over-investigate a simple febrile seizure.
Parental education and reassurance are the cornerstones of management.
Antipyretics treat fever and improve comfort but do not prevent seizure recurrence.
Key Resources:
Local Guideline: Paediatric Protocols for Malaysian Hospitals, 4th Edition. (This is your primary reference).
UpToDate: Febrile seizures: Clinical features and evaluation
StatPearls: Febrile Seizure
