Febrile Seizure Evaluation

On this April Fool’s Day, do not let the seizing patient with a fever make a fool of you.

Naturally, anytime a patient has a fever and a seizure, the first concerning diagnosis that comes to mind is meningitis; however, we are all aware of the unique entity that exists with children that makes you breathe more easily: febrile seizure. We breathe more easily because we know that the patient with a simple febrile seizure is unlikely to have a serious bacterial infection in their CSF. But, before we become complacent and cavalier, first ensure that the patient’s history fits the definition of simple febrile seizure.

1. Diagnosis: Simple vs Complex

  • Simple Febrile Seizure
    • Age = 6mos to 5yrs
    • Single Seizure in 24 hours
    • Generalized
    • Lasting less than 15 minutes
    • Child returns to baseline and has normal neurological exam; usually after a brief post-ictal period.
  • Complex Febrile Seizure
    • Same as above, except can be focal seizure or prolonged or with multiple seizures within 24 hours.
    • May indicate a more serious disease process.


2. The Work-Up:

  • The work-up is the work-up that is appropriate for the patient’s fever (simply put).
  • There has been a fair amount of debate over the utility of LP, particularly in those who are 12months of age or less. The AAP now advocates for the following:
    • Clinical Signs of meningitis – LP (you betcha!)
    • In infants 6-12mos who are deficient in their Hib or Strep. Pneumoniae vaccinations – LP is “an option.” (it is also your option to not perform it).
    • In infants 6-12mos who have be “pretreated” with antibiotics – LP is an “option” (not sure exactly what constitutes “pre-treatment” though).
    • No neuro imaging or EEGs are necessary for simple febrile seizures.
    • No bloodwork is necessary for simple febrile seizures. (Fingerstick glucose if the kid is still a little goofy by the time you see him wouldn’t be that far of a reach to suggest though).


3. My modest opinions:

  • Make the diagnosis by the definition.
  • Don’t forget to evaluate the fever (ie, 6 mos female, check the urine)
  • Immunization status is always important to inquire specifically about.
  • This is another good reason to not throw antibiotics at kids without a clear reason… inevitably that child started on amoxicillin yesterday because of a “mysterious acute otits media” that you can’t appreciate today will be the patient that you are evaluating for febrile seizure. That throws a wrench into the works.
  • Always hold Meningitis highest on your differential for fever and seizure and document why you do not think that this is Meningitis
    • “meets criteria for simple febrile seizure”
    • “no petechial rash, no purura”
    • “neck supple with FROM”
    • “Alert and tearing apart the examination room.”
  • 25% of kids with meningitis may present as a new onset seizure, but will often either have persistent altered mental status or other concerning findings (petechiae, focal seizure, nuchal rigidity). Actively look for this findings and document accordingly.


Subcommittee on Febrile Seizures. Clinical Practice Guideline – Neurodiagnostic Evaluation of the Child with a Simple Febrile Seizure. Pediatrics Vol 127, Num 2, Feb 2011, PP. 389-394.

Sean M. Fox
Sean M. Fox

I enjoy taking care of patients and I finding it endlessly rewarding to help train others to do the same. I trained at the Combined Emergency Medicine and Pediatrics residency program at University of Maryland, where I had the tremendous fortune of learning from world renowned educators and clinicians. Now I have the unbelievable honor of working with an unbelievably gifted group of practitioners at Carolinas Medical Center. I strive every day to inspire my residents as much as they inspire me.

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