• A simple febrile seizure (SFS) is generalized, tonic-clonic in type, and occurs in children between the ages of 6 months and 6 years of age, lasting less than 15 minutes and NON-recurring in a 24 hour period.
• According to the 1996 guidelines of the American Academy of Pediatrics (AAP) and based on the consensus that seizure is a common presenting symptom of bacterial meningitis, the following indications should be used to determine whether lumbar puncture (LP) is performed in patients presenting with SFS:

             --  6 to 12 months  >  "strongly consider" LP

              --  12 to 18 months  >  "consider" LP

              --  18 months and up  >  LP not routinely necessary; may consider after clinical assessment

              --   Any infant/child with recent antibiotic treatment plus SFS  >  "strongly consider" LP

• Despite these relatively outdated guidelines based largely on retrospective data, more recent literature suggests that serious bacterial infections such as meningitis are very rarely associated with simple febrile seizures, such that guidelines and practice paradigms may soon change.   

References

• American Academy of Pediatrics, Provisional Committee on Quality Improvement, Subcommittee on Febrile Seizures. Practice Parameter: The Neurodiagnostic Evaluation of the Child with a First Simple Febrile Seizure. Pediatrics. 1996; 97(5): 769-772.
• Kamia AA, et al. Utility of Lumbar Puncture for First Simple Febrile Seizure Among Children 6 to 18 Months of Age. Pediatrics. 2009;123:6-12.