What is the most likely diagnosis and urgent management for an 8‑month‑old infant who had a 1‑2‑minute seizure‑like event during a fever of 41 °C, now reduced to 39.4 °C after ibuprofen and acetaminophen (paracetamol), with negative viral testing?

Simple Febrile Seizure – Diagnosis and Management

This 8-month-old infant most likely experienced a simple febrile seizure, which is a benign, self-limited event requiring no anticonvulsant therapy or routine diagnostic testing beyond identifying the fever source. 1, 2

Diagnostic Classification

This presentation meets all criteria for a simple febrile seizure: 1, 2, 3

• Age: 8 months (within the 6 months to 5 years range) 1, 2
• Duration: 1-2 minutes (less than 15 minutes) 1, 2
• Seizure type: Generalized (no focal features described) 1, 2
• Frequency: Single episode within 24 hours 1, 2
• Temperature: ≥38.0°C (41°C documented) 1

The negative viral swabs do not change management—most febrile seizures occur with benign viral infections that may not be identified on routine testing. 1

Urgent Management Priorities

Immediate Assessment (Already Completed)

The seizure has already self-terminated, which is typical—most febrile seizures resolve spontaneously within 1-2 minutes. 4 The fever has been appropriately treated with antipyretics for comfort. 1

Critical Decision: Does This Infant Need Lumbar Puncture?

For infants under 12 months with fever and seizure, lumbar puncture should be strongly considered because meningeal signs may be absent in up to one-third of bacterial meningitis cases. 1, 2, 3

Specific indications for lumbar puncture in this 8-month-old: 1, 3

• Age < 12 months (this patient qualifies) 1, 3
• Incomplete immunization status for Haemophilus influenzae type b or Streptococcus pneumoniae 3
• Any clinical signs of meningitis: altered mental status, irritability, poor feeding, bulging fontanelle, neck stiffness 1
• Pre-treatment with antibiotics (if applicable) 3
• Failure to return to baseline within 5-10 minutes after seizure 4

If the infant is fully immunized, well-appearing, and has returned to baseline, lumbar puncture becomes optional rather than mandatory, though many clinicians would still perform it given the age. 3

What NOT to Do

No routine diagnostic testing is indicated for simple febrile seizures: 2, 3

• No EEG (explicitly inappropriate for simple febrile seizures) 2
• No neuroimaging (CT or MRI not indicated) 2, 3
• No routine blood tests beyond those needed to identify fever source 3
• No anticonvulsant prophylaxis (phenobarbital, valproic acid, diazepam, or any other medication) 1, 2, 5

Fever Source Evaluation

Direct attention toward identifying the cause of fever: 3

• Urinalysis is the most important test—urinary tract infection is the most common serious bacterial infection in this age group 1
• Physical examination for otitis media, pharyngitis, pneumonia 1
• Chest radiography only if respiratory signs present (tachypnea, retractions, crackles) 1

Disposition and Follow-Up

Criteria for Outpatient Management 1

The infant can be discharged home if:

• Good general condition (well-appearing, interactive) 1
• Normal urinalysis 1
• Returned to baseline neurologically 1
• Parents able to monitor and return if deterioration 1
• No signs of serious bacterial infection 1

Criteria for Hospitalization 1

Admit if any of the following:

• Age < 3 months (not applicable here, but close) 1
• Toxic or ill appearance 1
• Abnormal cerebrospinal fluid (if lumbar puncture performed) 1
• Difficulty feeding, persistent vomiting, or decreased urine output 1
• Seizure lasting > 5 minutes 4
• Failure to return to baseline within 5-10 minutes 4

Mandatory Follow-Up 1

• Reevaluation within 24 hours (either in-person or by phone) 1
• Parent education on warning signs: worsening general condition, skin rash (petechiae/purpura), respiratory distress, feeding refusal, excessive irritability or somnolence 1

Parent Counseling: The Most Important Intervention

Reassurance and education are the cornerstone of management—not medication. 2, 5

Prognosis (Excellent) 2, 5

• No long-term harm: Simple febrile seizures cause no decline in IQ, academic performance, neurocognitive function, behavior, or structural brain damage 2, 5
• Epilepsy risk: Approximately 1% by age 7 (identical to general population) 2, 5
• Even high-risk children (multiple seizures, age < 12 months at first seizure, family history of epilepsy) have only 2.4% risk of epilepsy by age 25 2

Recurrence Risk 2, 5

• Overall recurrence: Approximately 30% 1
• Age < 12 months at first seizure: 50% probability of recurrence 2
• Age > 12 months at first seizure: 30% probability of recurrence 2
• After second seizure: 50% will have at least one more 2

Antipyretics Do NOT Prevent Seizures 4, 1, 2, 5

Critical teaching point: Acetaminophen and ibuprofen should be used for the child's comfort and to prevent dehydration, but they do not prevent febrile seizures or reduce recurrence risk. 4, 1, 2 Two meta-analyses in 2021 demonstrated no benefit of antipyretics for seizure prevention. 4

Home Management of Future Seizures 4, 1

If another seizure occurs: 4

• Position the child on their side 4
• Remove harmful objects from the environment 4
• Protect the head from injury 4
• Never restrain the child 4
• Never put anything in the mouth 4
• Call 911 if: seizure lasts > 5 minutes, difficulty breathing, seizure in water, traumatic injury, or failure to return to baseline within 5-10 minutes 4

Common Pitfalls to Avoid

1. Prescribing anticonvulsant prophylaxis: The American Academy of Pediatrics explicitly recommends against continuous or intermittent anticonvulsants (phenobarbital, valproic acid, diazepam, clobazam) because potential toxicities outweigh minimal benefits. 1, 2, 5

2. Ordering unnecessary tests: EEG, CT, MRI, and routine blood work are not indicated for simple febrile seizures and waste resources while potentially causing harm. 2, 3

3. Failing to consider meningitis in young infants: The age of 8 months is in the gray zone where lumbar puncture should be strongly considered, especially if immunization status is incomplete or the infant appears ill. 1, 3

4. Telling parents antipyretics prevent seizures: This common misconception leads to parental anxiety and aggressive fever management without benefit. 4, 1, 2

5. Missing urinary tract infection: This is the most common serious bacterial infection in febrile infants and requires urinalysis for detection. 1