Febrile Seizure

What is a febrile seizure?

A febrile seizure is abnormal electrical activity in your child’s brain that can happen while your child has a fever. Some of the most common symptoms include uncontrollable shaking (convulsions) and a short-term loss of consciousness.

These seizures affect children between 6 months and 5 years of age. They most commonly occur in the first three years of life.

Most febrile seizures aren’t dangerous, but they can be worrying for new parents and caregivers. A healthcare provider should evaluate your child when they happen.

What are the types of febrile seizures?

There are two types of febrile seizures:

• Simple febrile seizure: The seizure lasts fewer than 15 minutes. It usually causes a loss of consciousness and uncontrollable movements. Your child only has one seizure in 24 hours.
• Complex febrile seizure: The seizure lasts longer than 15 minutes. There could be pauses between convulsions or movements could happen constantly. Sometimes, symptoms only affect one side of their body. More than one seizure can happen within 24 hours.

What are the symptoms of a febrile seizure?

The symptoms of a febrile seizure may include:

• Uncontrollable muscle movements (convulsions) that may look like your child is shaking. Their muscles may stiffen or tense up or they’ll experience muscle twitching.
• Loss of consciousness (passing out). Your child’s eyes may roll back as this happens.
• Loss of bodily control (drooling, vomiting, peeing or pooping).

These symptoms usually only last for a couple of seconds to minutes with simple febrile seizures. They may last more than 15 minutes or happen more than once in a day with complex types.

What causes a febrile seizure?

There are many potential causes for febrile seizures. The word “febrile” refers to a fever. They’re most likely to happen during the first day of an illness as your child's temperature rises. A commonly reported temperature is above 101 degrees Fahrenheit (38.3 degrees Celsius), but this can vary. The following illnesses may cause a fever:

• Chickenpox.
• Coronavirus (COVID-19).
• Ear infection.
• Flu (influenza).
• RSV (respiratory syncytial virus).
• Upper respiratory infection.

In some cases, children will have a seizure before developing a fever.

While rare, it’s important to note that some childhood vaccinations may cause a fever as a side effect. If a child has a febrile seizure after vaccination, it’s the fever, not the vaccine itself, that causes the seizure.

Central nervous system infections like encephalitis and meningitis don’t cause this condition, but they can cause different types of seizures that aren’t the result of a fever.

Is a febrile seizure genetic?

Yes, there are certain genes associated with febrile seizures that increase your child’s risk of having one. Between 10% and 33% of children who have a febrile seizure have a biological relative who has a history of seizures.

What are the risk factors for a febrile seizure?

This condition is relatively common — they’re the most common type of seizure that happens during childhood. Your child may be more at risk of having a febrile seizure if they:

• Are an infant (under 12 months) or younger than 5 years old.
• Were hospitalized in the neonatal intensive care unit for more than 28 days.
• Have developmental delay.
• Have an infection.
• Have a biological family history of seizures.

Sometimes, seizures only happen once, but your child may face a greater risk of having more than one seizure if:

• Their first seizure was before 12 months.
• They have a biological family history of seizures.
• A seizure is the first sign of an illness (before any other symptoms occur).

What are the long-term effects of a febrile seizure?

Febrile seizures are usually harmless and don’t typically cause long-term effects.

Your child may have more than one seizure before they turn 5. While less common, if they have several seizures, studies have found that your child might have trouble meeting language development milestones for their age.

Research has also found that complex febrile seizures may slightly increase your child’s risk of a future seizure disorder.

How is a febrile seizure diagnosed?

To diagnose this condition, a healthcare provider will review your child’s medical history and perform a physical exam. These may happen in an emergency room setting or their provider’s office. Your child’s provider will take their temperature and review their symptoms. They may order a blood or urine test to diagnose what caused the fever.

How is a febrile seizure treated?

If your child has a first-time febrile seizure, they may recover from it fairly quickly. But you should contact your child’s healthcare provider or visit the emergency room to verify that this seizure is, in fact, a febrile seizure and not caused by something more serious.

A provider may offer treatment recommendations or supportive care for the cause of the fever. This may include taking age-safe acetaminophen (Tylenol®), ibuprofen (Motrin®) or other medications as directed.

Complex febrile seizure medications

Complex febrile seizures (a seizure that lasts longer than five minutes or if your child has more than one seizure in 24 hours) are more likely to need treatment. Your child’s provider may recommend the following medications:

• Intranasal (given through the nose) midazolam.
• Intravenous (injection into a vein) benzodiazepines.
• Rectal (given through the rectum) diazepam.

What to do during a febrile seizure

If your child has a history of this condition, their healthcare provider can guide you on seizure first aid and what to do to treat these at home. In general, you should do the following:

• Stay calm. Seeing your child having a seizure can be very frightening, but it’s important for you to keep as calm as possible.
• Track the time. Note how long your child’s seizure lasts. If the seizure lasts more than five minutes, you should immediately call 911 (or your local emergency services number).
• Slowly and gently set your child down on the floor. Don’t place your child on a table or bed, and don't try to hold them in your arms or hold them down. These actions increase the risk of an injury.
• Place them on their side. Lay your child on their side. This prevents choking from fluid (saliva or vomit) going into their lungs.
• Don’t put anything in their mouth. Move any objects away or out of your child’s mouth to prevent choking.

Can a febrile seizure be prevented?

Febrile seizures happen unpredictably and aren’t usually preventable. Even if you treat your child’s fever, they’re still at risk of having one.

What can I expect after a febrile seizure?

Every child responds differently after seizures. It’s common for your child to feel confused and tired when they regain consciousness. Your child may need a few minutes until they start acting more like themselves. It’s important to keep a close eye on your child. Make sure they take it easy and they’re resting. Keep in contact with your child’s provider and follow any instructions they offer.

How long do febrile seizures last?

Febrile seizures usually only last for a couple of minutes. The simple type may last for a few seconds up to 15 minutes and the complex type may last longer than 15 minutes.

It’s important to keep track of the time. A less common complication is febrile status epilepticus. This is when a seizure lasts more than 30 minutes. This is a medical emergency.

When should I see a healthcare provider?

All first-time febrile seizures need medical attention. You should contact a healthcare provider or emergency services if your child has a seizure for the first time.

If your child has a history of seizures, your child’s pediatrician can offer the best guidance on what you can and should do to treat these. They can also tell you about any signs that you need to look out for.

When should I go to the ER?

You should get emergency medical care for febrile seizures in any of the following situations:

• This is the first seizure for your child.
• The seizure lasts more than five minutes.
• Your child has trouble breathing.
• Your child has symptoms of a brain or spinal cord infection (neck stiffness or pain, lethargy, frequent vomiting).
• Your child is slow to recover (it takes an hour or more to return to normal).
• Your child is injured during the seizure.