Most febrile seizures occur because of a sudden spike in body temperature, and most occur during the first day of a fever.
Viral or bacterial infection
Usually, the fevers that trigger febrile seizures are caused by a bacterial or viral infection in your child's body. Typical childhood illnesses, including respiratory illnesses and infections such as roseola — a viral illness that causes swollen lymph nodes, usually in the neck, and a rash — are often associated with febrile seizures. A less common but very serious cause of sudden fever with seizures is an infection of a child's brain and spinal cord (central nervous system), such as meningitis or encephalitis. These illnesses may also cause seizures without a fever.
The risk of febrile seizures may increase after some childhood immunizations, such as the diphtheria, tetanus and pertussis (DTP) or measles-mumps-rubella (MMR) vaccinations. Low-grade fevers can sometimes occur after your child receives childhood vaccines. If a febrile seizure occurs, it's caused by the fever that may accompany the vaccination — not by the vaccination itself.
Jan. 24, 2012
- Febrile seizures fact sheet. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/febrile_seizures/detail_febrile_seizures.htm. Accessed Nov. 14, 2011.
- What do I do if my child has a febrile seizure? American Academy of Pediatrics. http://www.aap.org/publiced/BR_FebrileSeizures.htm. Accessed Nov. 14, 2011.
- American Academy of Pediatrics. Clinical practice guideline — Febrile seizures: Guideline for the neurodiagnostic evaluation of the child with a simple febrile seizure. Pediatrics. 2011;127:389.
- Febrile seizures. The Merck Manuals: The Merck Manual for Healthcare Professionals. http://www.merckmanuals.com/professional/pediatrics/neurologic_disorders_in_children/febrile_seizures.html. Accessed Nov. 14, 2011.
- Bernard TJ, et al. Neurologic & muscular disorders. In: Hay WW, et al. Current Diagnosis & Treatment: Pediatrics. 20th ed. New York, N.Y.: The McGraw-Hill Companies; 2011. http://www.accessmedicine.com/content.aspx?aID=6585048. Accessed Nov. 13, 2011.
- Cendes F, et al. Vaccinations and febrile seizures. Epilepsia. 2011;52(suppl):23.
- Sullivan JE, et al. Fever and antipyretic use in children. Pediatrics. 2011;127:580.
- Hoecker JL (expert opinion). Mayo Clinic, Rochester, Minn. Nov. 10, 2011.
- Nickels KC (expert opinion). Mayo Clinic, Rochester, Minn. Nov. 21, 2011.