Basics
Description
- Occurs between 6 mo and 5 yr of age associated with fever:
- No evidence of intracranial infection or other defined CNS primary cause
- Average age of onset is 18 " 22 mo
- Children with previous nonfebrile seizures excluded
- Most common pediatric convulsive disorder:
- Affects 2 " 4% of young children in US
- Occurs in normal children with a systemic viral illness
- High-risk children:
- History of febrile seizure in immediate family members
- Delayed neurologic development
- Males
- Subgroups:
- Simple febrile seizures:
- Brief, self-limited lasting <10 " 15 min, resolve spontaneously
- Generalized without any focal features
- Complex febrile seizures:
- Duration >15 min
- Focal features
- More than 1 seizure within a 24-hr period
- Risk of recurrence:
- One-third of cases
- Early age of onset, history of febrile or afebrile seizures in 1st-degree relatives, and temperature <40 °C during initial seizure increase the likelihood of recurrence
- Risk of subsequent epilepsy:
- Greatest for those with prior abnormal neurologic development, a complex (>15 min) 1st febrile seizure, a focal seizure, or a family history of afebrile seizures
- Only slightly greater than the general population if 1st febrile seizure is simple and neurologic development normal
- Not affected by the use of prophylactic medications
Because this is usually self-limited, intervention must be individualized in relation to airway, breathing, and seizure management
Etiology
Common childhood infections:
- Upper respiratory illnesses
- Otitis media
- Roseola
- GI infections
- Shigella gastroenteritis
Diagnosis
Signs and Symptoms
- Fever
- Seizure may occur concurrent with recognition of the febrile illness
- Seizure
- Generalized tonic " clonic seizure most common:
- Tonic phase:
- Muscular rigidity
- Apnea and incontinence
- Self-limited and last only a few minutes
- Other seizure types:
- Staring with stiffness
- Limpness
- Jerking movements without prior stiffening
History
- Careful history and physical exam help confirm diagnosis and rule out other etiologies
- Symptoms/evidence of infectious illness
- Duration and pattern of fever
- Medication exposure/toxin
- Recent immunizations
- Trauma/occult trauma
- Growth pattern and developmental level
- Family history of seizures
- Complete description of seizure
Physical Exam
- Reducing temperature may be useful in evaluation; give antipyretics early
- Evidence of infectious illness-rash, ear infection, respiratory infection, diarrhea, etc.
- Careful neurologic exam including mental status
- Presence of meningismus, bulging fontanelle, nuchal rigidity, etc.
- Evidence of focal deficit or increased ICP
Diagnosis Tests & Interpretation
Lab
- Routine lab studies not indicated
- Evaluate for a source of fever if serious bacterial infection is suspected:
- WBC
- UA
- Blood and urine cultures
- Lumbar puncture:
- Not routinely indicated
- Indications 12 " 18 mo of age:
- History or irritability, decreased feeding, lethargy
- Consider if deficient in Haemophilus influenzae type b or Streptococcus pneumoniae immunizations
- Physical signs of meningitis and/or history consistent with meningitis
- Complex seizure
- Prolonged postictal state
- Prior antibiotics altering presentation
- Abnormal mentation after postictal state
- Indications >18 mo old:
- Signs/symptoms of CNS infection present
- Electrolytes and bedside glucose in infants and children with vomiting or diarrhea
- EEG:
- Not helpful in the initial evaluation of febrile seizures
- May be indicated if developmental delay, underlying neurologic abnormality, or focal seizure
- Does not help predict recurrences or risk for later epilepsy
- Anticonvulsant levels
- Toxicology studies of blood and urine if history and physical exam suggestive
Imaging
- Chest radiograph only in patients with significant respiratory symptoms or pertinent findings on physical exam
- Head CT:
- Indicated with traumatic injuries, focal neurologic findings, or inability to exclude elevated intracranial pressure
Differential Diagnosis
- Febrile delirium
- Febrile shivering with pallor and perioral cyanosis
- Breath-holding spell during febrile event
- Acute life-threatening event
- Other causes of seizure:
- Afebrile seizure occurring during febrile event
- Sudden discontinuance of anticonvulsants
- Infection:
- Meningitis/encephalitis
- Acute gastroenteritis, often with dehydration
- Head trauma
- Toxicologic:
- Anticholinergics
- Sympathomimetics
- Other
- Hypoxia
- Metabolic disease
- Intracranial masses
- CNS vascular lesions
Treatment
Pre-Hospital
- Protect the airway
- Oxygen
- Support breathing as needed
- Cautions:
- Keep child from incurring injury while actively convulsing
- Respiratory insufficiency and apnea occur secondary to overaggressive treatment with benzodiazepines
- Simple febrile seizures are self-limited and generally require no anticonvulsant therapy or ventilatory support
Initial Stabilization/Therapy
- Support the airway and breathing
- Benzodiazepines rarely needed:
- Prolonged seizures or compromised patients
- Lorazepam, diazepam, or midazolam
- Rectal diazepam or nasal midazolam may be easily administered with good efficacy
Ed Treatment/Procedures
- Rarely is pharmacologic intervention required; usually self-limited
- Seizures refractory to benzodiazepines:
- Phenytoin or fosphenytoin
- Phenobarbital
- Workup to exclude other etiologies
- Administer antipyretics acutely and routinely for at least the next 24 hr:
- Acetaminophen and/or ibuprofen (may use both)
- Appropriate antibiotic treatment for specific bacterial disease if identified
- Reassure and education of parents is essential
Medication
- Acetaminophen: 10 " 15 mg/kg/dose PO, PR; do not exceed 5 doses/24 h
- Diazepam: 0.2 mg/kg IV (max. 10 mg); 0.2 " 0.5 mg/kg PR (max. 20 mg)
- Fosphenytoin: 20 mg/kg IV over 20 min
- Ibuprofen: 10 mg/kg PO
- Lorazepam: 0.1 mg/kg IV (max. 5 mg)
- Midazolam: 0.05 " 0.1 mg/kg IV; 0.2 mg/kg buccal/IN/IM (max. 7.5 mg)
- Phenobarbital: 15 " 20 mg/kg IV over 20 min or IM; monitor for respiratory depression
- Phenytoin: 15 " 20 mg/kg IV over 30 " 45 min
Follow-Up
Disposition
Admission Criteria
- Recurrent or prolonged seizures
- Fever with source not appropriately treated as outpatient
Discharge Criteria
- Simple febrile seizures:
- Normal neurologic exam
- Source of fever is appropriately treated as outpatient
- Reassurance to parents
Followup Recommendations
Schedule follow-up with primary care physician
Pearls and Pitfalls
- Although aggressive treatment of fever with antipyretics is often recommended, there is no evidence that this reduces seizure recurrence
- Oral diazepam during febrile illness may reduce risk of recurrence; prophylactic anticonvulsants with other anticonvulsants rarely indicated " such treatment is controversial and to be considered only after extensive discussion
Additional Reading
- Barata I. Pediatric seizures. Crit Decisions Emerg Med. 2005;19(6):1 " 21.
- Blumstein MD, Friedman MJ. Childhood seizures. Emerg Med Clin North Am. 2007;25:1061 " 1086.
- Hirabayashi Y, Okumura A, Kondo T, et al. Efficacy of a diazepam suppository at preventing febrile seizure recurrence during a single febrile illness. Brain Dev. 2009;31:414 " 418.
- Offringa M, Newton R. Prophylactic drug management for febrile seizures in children. Cochrane Database Syst Rev. 2012;4:CD003031.
- Steering Committee on Quality Improvement and Management; Subcommittee on Febrile Seizures American Academy of Pediatrics. Febrile seizures: Clinical practice guideline for the long-term management of the child with simple febrile seizures. Pediatrics. 2008;121(6):1281 " 1286.
- Strengell T, Uhari M, Tarkka R, et al. Antipyretic agents for preventing recurrences of febrile seizures: Randomized controlled trial. Arch Pediatr Adolesc Med. 2009;163(9):799 " 804.
- Subcommittee on Febrile Seizures; American Academy of Pediatrics. Neurodiagnostic evaluation of the child with a simple febrile seizure. Pediatrics. 2011;127(2):389 " 394.
See Also (Topic, Algorithm, Electronic Media Element)
- Anticholinergic Poisoning
- Seizures, Pediatric
- Fever, Pediatric
Codes
ICD9
- 780.31 Febrile convulsions (simple), unspecified
- 780.32 Complex febrile convulsions
ICD10
- R56.0 Febrile convulsions
- R56.00 Simple febrile convulsions
- R56.01 Complex febrile convulsions
SNOMED
- 41497008 Febrile convulsion (finding)
- 433083002 Complex febrile seizure
- 432354000 Simple febrile seizure
- 307200007 Recurrent febrile convulsion (finding)