Nov 24, 2020, 9:57:53 AM CST Nov 30, 2023, 1:29:29 PM CST

What is a febrile seizure?

Approximately 2-5% of children experience seizure triggered by fever. Learn the signs and what to do.

Boy with fever Boy with fever

A febrile seizure is a seizure triggered by fever. It is the most common type of seizure in infants and young children, occurring in about 2-5% of children under the age of 5. A febrile seizure is not considered a form of epilepsy, but if a child has a febrile seizure, it's important to work with a physician to determine the cause of fever and rule out any other conditions.

Febrile seizures are classified into two types:

  • Simple febrile seizures: Simple febrile seizures are the most common type of febrile seizure. They affect the entire body, and typically last a few seconds up to 15 minutes. Simple febrile seizures do not recur within 24 hours.
  • Complex febrile seizures: Complex febrile seizures affect one part of the body, last longer than 15 minutes and occur more than once within 24 hours while the child is running a fever.

What causes febrile seizures?

Febrile seizures are caused by fever (a temperature of 100.4°F or above). Typically, the higher the fever, the higher the risk of febrile seizure; however, in children who are susceptible to febrile seizures, even a low fever may trigger a seizure. In some cases, a parent may not even know a child is starting to spike a fever until after the seizure occurs.

Children between the ages of 6 months and 3 years old are more likely to experience a febrile seizure.

A young child's developing brain has a much lower seizure threshold – meaning it doesn't take as much to trigger a seizure as it would in an older child.

Febrile seizures can run in families, and approximately 40% of children who have one febrile seizure will have a recurrence. Children at higher risk for febrile seizures include children who:

  • Had their first febrile seizure before 18 months old
  • Have a family history of febrile seizures
  • At the first sign of illness, have a febrile seizure

Although very frightening for a parent to watch, febrile seizures generally don't last long and usually do not cause any long-term health problems.

What does a febrile seizure look like?

A febrile seizure in a child most often presents as convulsions, but a child may experience different symptoms. It may be hard to determine the difference between typical fever chills and a convulsion. Common febrile seizure symptoms include:

  • Loss of consciousness
  • Body or muscle contraction and stiffness such as convulsions
  • Biting of cheek or tongue
  • Clenched teeth or jaw
  • Rolling of the eyes back in the head
  • Loss of bladder or bowel control

Can you prevent febrile seizures?

Most febrile seizures are brief and do not harm the child's development. Anti-seizure medication is unnecessary to treat febrile seizures; however, children who have a history of prolonged febrile seizures or those living in remote communities should talk to their doctor about a rescue medication to be used only as needed and prescribed by the doctor.

Using a fever-reducing medicine such as acetaminophen or ibuprofen can help bring down fever in children, but may not prevent a febrile seizure. Children who are prone to having febrile seizures when they have a high fever should be seen by their doctor.

About 50% of the children who have their first febrile seizure before turning age 1 will experience a second febrile seizure. However, the majority of children with febrile seizures will not have seizures without fever after the age of 5.

What to do if your child has a febrile seizure

One of the most important things a parent can do during a seizure is not to panic. When you remain calm, you're better able to help keep your child safe from harm's way.

If your child is having a febrile seizure, follow the steps for seizure first aid:

  • Time the start and end of seizure.
  • Gently place the child on a comfortable surface, such as a carpeted floor.
  • Position the child on their side.
  • Do not grab or hold your child during a convulsion.
  • Do not place anything in the child's mouth.
  • Call 911 if the seizure lasts longer than 5 minutes, or is less than 5 minutes, but the child does not seem to be recovering quickly.
  • Seek immediate medical attention if this is the child's first febrile seizure.

If your child has never had a seizure before and has a seizure while having a fever, it's important to get your child evaluated by a physician. While febrile seizures are often not harmful, a high fever with seizure may be the result of a serious infection such as meningitis.

Learn more

Designated as a Level 4 Epilepsy Center by the National Association of Epilepsy Centers, Children's Medical Center Dallas provides the highest level of treatment for the most complex cases of pediatric epilepsy, with additional advanced epilepsy treatment options available at our Level 3 Epilepsy Center in Plano. Learn more about our Pediatric Epilepsy Center at Children's Health℠.

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