A febrile seizure is a convulsion (shaking, twitching, muscle tightness) or fainting associated with a fever. It occurs in infants or small children. This seizure is not associated with any other illness or medical condition except the fever.
There are two types of febrile seizures:
Simple febrile seizures:
- Convulsions last between a few seconds to 15 minutes
- Seizures are followed by a period of confusion and sleepiness which slowly goes away
Complex febrile seizures:
- Last longer than 15 minutes
- Occur more than once within 24 hours
- Convulsions which affect only part the body
Febrile seizures can be alarming. Fortunately, children tend to outgrow these seizures. There is also a low risk for long term physical or mental disorders.
High body temperature due to a fever is believed to trigger the seizure. The fever is most often caused by common viral infections. Some febrile seizures may be caused by fever after routine immunizations.
Age is the greatest risk factor. Febrile seizures occur between the ages of 3 months to 5 years. Most febrile seizures occur in children between 6 months to 3 years of age. In general, the younger the age that the first febrile seizure occurs, the more likely it is that a child will have another seizure.
There is some evidence that febrile seizures may run in families.
A seizure typically lasts a few seconds to a few minutes. Signs of a febrile seizure include:
- A fever, usually above 102°F (38.9ºC)
- Convulsion—jerking or stiffening muscles
- Abnormal eye movements
- Coarse breathing sounds during the convulsion
- Loss of consciousness
- Loss of bladder or bowel control
- Brief period of drowsiness or confusion following a seizure
If you suspect your child is having a febrile seizure, stay calm and follow these steps:
- Unless the doctor has told you otherwise, call for emergency medical services.
- Protect your child from physical injury. Place your child on the floor or bed away from any hard or sharp objects.
- Protect your child's airway. Do not place anything in the mouth during the convulsion. Turn the child’s head or body to the side. This will allow saliva or vomit to drain from the mouth.
- Watch the time. The length of the convulsions should be less than 5 minutes.
Febrile seizure is diagnosed based on information about the seizure and your child's health.
Your child's bodily fluids may be tested. This can be done with:
- Blood tests
- Urine tests
- Lumbar puncture
Images may be taken of your child's head. This can be done with:
Your child's brain function may be tested. This can be done with an electroencephalogram (EEG).
Children will eventually outgrow febrile seizures. The treatment goal is to manage fevers that may cause seizures. This may be done by treating the underlying infection. The treatments may include medication.
To address the underlying cause of fever your child's doctor may advise:
- Antiviral medications
- Acetaminophen or ibuprofen to lower the fever
Note: Aspirin is not recommended for children or teens with a current or recent viral infection. This is because of the risk of Reye's syndrome. Ask your doctor which medications are safe for your child.
Your doctor may advise a rectal valium gel. This gel can interrupt seizures. It may be recommended if your child has frequent seizures and the seizure lasts more than 4-5 minutes.
Fevers can happen suddenly. A seizure can be the first sign. As a result, there is no known way to prevent a febrile seizure.
Healthy Children—American Academy of Pediatrics
Canadian Paediatric Society—Caring for Kids
Febrile seizure. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated February 7, 2014. Accessed September 25, 2014.
Febrile seizures: what every parent should know. Family Doctor—American Academy of Family Physicians website. Available at: http://familydoctor.org/familydoctor/en/diseases-conditions/febrile-seizures.html. Updated March 2014. Accessed July 20, 2012.
National Institute of Neurological Disorders and Stroke (NINDS) febrile seizures information page. National Institute of Neurological Disorders and Stroke website. Available at: http://www.ninds.nih.gov/disorders/febrile_seizures/febrile_seizures.htm. Updated April 16, 2014. Accessed September 25, 2014.
Strengell T, Uhari M, Tarkka R, et al. Antipyretic agents preventing recurrences of febrile seizures: randomized controlled trial. Arch Pediatr Adolesc Med. 2009 Sep;163(9):799-804.
Last reviewed August 2014 by Kari Kassir, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.