Febrile seizure is a condition of sudden convulsions and loss of consciousness that develops due to high fever, especially in children between 6 months and 5 years of age. In most cases it does not leave permanent damage, but recurrent seizures should be carefully evaluated because they may increase the risk of epilepsy.

Risk factors for febrile seizures include family history, rapid rise in fever, and some viral infections. Although the first attack in children is usually worrying for families, risks can be managed correctly with an evaluation carried out under medical supervision.

Neurological evaluation is important in every child who experiences a febrile seizure. In recurrent attacks, EEG and, if necessary, brain imaging methods may be used. In this way, conditions that may progress to epilepsy can be detected early and a treatment plan can be made.

In an emergency, the first intervention is to keep the child in a safe position and reduce the fever. Drug treatment may be started in prolonged or recurrent seizures. Although most febrile seizures have a good prognosis, regular follow-up should not be neglected.

What Is a Febrile Seizure?

As the name suggests, a febrile seizure is a type of seizure triggered by fever caused by an infection in the body. You can think of it like an electrical circuit tripping when overloaded. While the child’s body fights an infection, the temperature rises and this sudden increase in heat can cause a temporary “short circuit” in sensitive brain cells. This short circuit manifests itself as contractions and tremors.

There is an important point: this condition is different from conditions such as meningitis or encephalitis, which are direct brain inflammations. Brain inflammation itself can also cause seizures, but a febrile seizure is the result of fever caused by an infection elsewhere in the body. For example, your child may have a throat infection, a urinary tract infection, or even a simple cold that can cause a febrile seizure. Febrile seizures are most commonly seen in children between 1.5 and 3 years of age. It is as if these ages are the period when the brain is most sensitive to such sudden temperature changes.

However, there are also some special situations. If a baby has had a febrile seizure before the age of 1, there may be some genetic causes underlying this condition that may begin with febrile seizures and later turn into afebrile seizures, that is, epilepsy. Therefore, it is important that children who have febrile seizures before the age of 1 are examined more closely by their doctor.

Another distinction should be made clearly: children who are neurologically abnormal, for example those with disorders such as cerebral palsy, are not described as having febrile seizures even if they experience seizures with fever. This is because the cause of seizures in these children may not be fever alone. Likewise, children who experience seizures with fever after the age of 6 are also not described as having “febrile seizures.” Their seizures are evaluated as epileptic seizures triggered by fever and are followed with a different approach.

What Causes Febrile Seizures?

We now know that the main cause is fever. So where does this fever usually come from? Most of the time, simple viral infections are responsible. Fever that rises during common childhood illnesses such as influenza, colds, sixth disease (roseola), or RSV (Respiratory Syncytial Virus) may trigger febrile seizures. More rarely, bacterial infections or conditions such as middle ear infection may also cause fever and therefore seizures.

Sometimes the seizure occurs at the moment when the fever rises most rapidly. In some cases, the seizure may even be the first sign that your child is ill. In other words, before you even notice the fever, the child may experience a seizure.

Some childhood vaccines (for example the combined vaccine, measles-mumps-rubella vaccine, or pneumococcal vaccine) may also cause fever within a few days after vaccination, which may lead to febrile seizures in some sensitive children. The important point here is that the seizure is caused not directly by the vaccine but by the fever caused by the vaccine.

So why do some children have seizures when they develop a fever while others do not? This is where genetic factors come into play. Febrile seizures are thought to generally occur as a result of genetic predisposition. Having individuals in the family who have previously experienced febrile seizures may increase the likelihood that the child will also experience them. However, this does not mean that your child will definitely have seizures. You can think of it like a predisposition to diabetes in some families. Not everyone becomes ill, but the risk is somewhat higher.

Who Experiences Febrile Seizures?

As mentioned above, febrile seizures are most commonly seen in children between 6 months and 6 years of age. Especially between 1.5 and 3 years of age is the period when this condition is most frequently experienced. It is as if the brains of little children in this age range are more vulnerable to sudden increases in temperature.

If your child is neurologically completely normal, meaning there is no brain damage or developmental delay, and experiences seizures with fever after the age of 6, this condition is no longer called a “febrile seizure.” These cases are evaluated as epileptic seizures triggered by fever and fall under a different specialty field.

It should also be remembered that in some children who experience febrile seizures before the age of 1, genetic causes that may later develop into epilepsy can be identified. Therefore, monitoring and, if necessary, genetic testing of children in this age group are important.

What Are the Types of Febrile Seizures?

Febrile seizures are basically divided into two types: simple febrile seizures and complex febrile seizures. Most children experience simple febrile seizures.

• Simple Febrile Seizure: These seizures usually last a short time, most often less than 15 minutes. They manifest as contractions and tremors involving the entire body. In other words, both your child’s arm and leg contract and tremble at the same time. A simple febrile seizure occurs only once within 24 hours and after the seizure your child usually regains consciousness within a short time and does not experience any permanent neurological problem. You can think of it like a short power outage. The lights go out, then come back on and everything returns to normal.
• Complex Febrile Seizure: These seizures are somewhat different. If one or more of the following characteristics are present, the seizure is described as complex:
• Duration: If the seizure lasts 15 minutes or longer. As if the power outage lasted longer.
• Body Involvement: If the contractions occur only on one side of the body. For example, tremors only in the right arm and leg.
• Temporary One-Sided Weakness: If temporary weakness or movement limitation develops on one side of the body after the seizure.
• Frequency: If more than one seizure occurs within 24 hours. As if the electricity keeps going on and off.

Complex febrile seizures may be associated somewhat more with certain long-term outcomes compared with simple ones, but we will address these topics later.

What Are the Symptoms of Febrile Seizures?

The symptoms you may observe in your child during a febrile seizure include:

• Loss of Consciousness: Your child may briefly lose consciousness or faint.
• Contractions and Tremors: Uncontrolled contractions, tremors, or stiffness may occur in the arms and legs. This condition may affect the entire body or only a part of it.
• Eye Rolling: The eyes may roll upward.
• Loss of Body Control: Conditions such as drooling, vomiting, urinary or stool incontinence may occur.
• Fever: Usually there is a fever of 38°C (100.4°F) or higher during or before the seizure. However, sometimes the seizure may begin before the fever rises.

What Should Be Done During a Febrile Seizure?

It is very important not to panic while your child is experiencing a febrile seizure, although of course this is not easy. First of all try to remain calm. Remove hard or sharp objects around that may be dangerous. Lay your child on the ground or on a soft surface in a side position. This position helps prevent fluids such as vomit or saliva from entering the lungs.

It is important to monitor how long the seizure lasts. Check your watch. Stay with your child and observe them. Loosen tight clothing. If there is something in the mouth that can be easily removed (for example a piece of food), gently remove it. However, never try to open your child’s mouth or place anything inside during the seizure. This may harm your child.

Do not try to stop the seizure and do not restrict your child’s movements. Febrile seizures usually stop on their own within a few minutes.

Seek emergency medical help in the following situations:

• If the seizure lasts longer than 5 minutes.
• If your child has seizures one after another.
• If your child does not regain consciousness immediately after the seizure.
• If this is your child’s first febrile seizure.
• If your child has symptoms of meningitis such as neck stiffness, excessive sleepiness, difficulty breathing, or severe vomiting.

How Is a Febrile Seizure Diagnosed?

After your child experiences a febrile seizure, your doctor will first take a detailed medical history and perform a physical examination. They will want to obtain information about your child’s developmental milestones, vaccination records, and illnesses they have had. The aim is to find the cause of the fever and rule out other possible conditions.

In a child who has experienced the first simple febrile seizure and whose vaccinations are complete, usually no further tests are required and the diagnosis can be made according to the child’s history and clinical findings.

However, additional tests may be necessary in some cases. Blood and urine tests may be performed to investigate serious infections in children whose vaccinations are incomplete or whose immune systems are weak. Especially in infants younger than 6 months, in children with symptoms of meningitis such as neck stiffness, or if a brain infection is generally suspected, lumbar puncture (removal of fluid from the lower back) may be performed to examine cerebrospinal fluid.

In cases of complex febrile seizures, prolonged seizures, or suspicion of predisposition to epilepsy, EEG (electroencephalography), which measures the electrical activity of the brain, may be performed. However, the routine use of EEG to predict the risk of future seizures after a simple febrile seizure is still a controversial issue.

In unusually prolonged complex febrile seizures, if there are neurological signs on one side of the body, if there are signs of increased intracranial pressure, or if the child’s head circumference is larger than normal, brain MRI (magnetic resonance imaging) may be recommended to evaluate whether there is a structural abnormality in the brain.

It should be remembered that routine blood tests, lumbar puncture, brain imaging, and comprehensive examinations such as EEG are usually not necessary in typical and uncomplicated febrile seizures.

How Is a Febrile Seizure Treated?

Most febrile seizures last a short time and stop on their own. Therefore, special medical treatment is usually not required to stop the seizure. However, in prolonged seizures lasting longer than 5 minutes, medication may be required to stop the seizure activity. Drugs such as rectal diazepam (suppository) or intranasal midazolam may be prescribed for home use in children at risk of prolonged or recurrent febrile seizures. In hospital settings, diazepam given intravenously or orally, or buccal midazolam, may be used.

Hospitalization is usually not required in simple febrile seizures. However, hospitalization may be considered in prolonged seizures, infants younger than 6 months, seizures occurring together with a serious infection, or cases where the source of the fever cannot be determined.

Although medications such as paracetamol or ibuprofen used to reduce fever may help your child feel more comfortable, these medications have not been shown to prevent febrile seizures.

Routine use of anticonvulsant (seizure-preventing) medications taken daily to prevent febrile seizures is generally not recommended. The reason is that these medications may have side effects and most febrile seizures are benign. However, in special high-risk situations such as frequent recurrent complex febrile seizures, limited access to medical care, or excessive parental anxiety, intermittent oral diazepam at the onset of fever may be considered.

Can Febrile Seizures Recur?

Yes, a child who has experienced a febrile seizure has a somewhat higher chance of having another seizure. The probability of recurrence is higher in children who were younger than 18 months when they had their first seizure, in those with a family history of febrile seizures, or when the first seizure occurred before the fever rose very high. However, most children experience febrile seizures only a few times and then the condition disappears on its own.

Is There a Risk of Epilepsy After a Febrile Seizure?

This is one of the issues that parents wonder about the most. After a simple febrile seizure, the risk of developing epilepsy is quite low, only slightly higher than the risk in the general population (estimated around 1–2%).

In children who experience complex febrile seizures or prolonged febrile seizures (also known as febrile status epilepticus), this risk may increase somewhat. In addition, the risk of developing epilepsy after a febrile seizure may be slightly higher in children who already have neurological problems.

However, it should be remembered that children who experience simple febrile seizures generally show the same performance as their peers in terms of academic success, intelligence levels, and behavior in the long term.

Genetic Factors and Febrile Seizures

As mentioned earlier, febrile seizures generally occur as a result of genetic predisposition. Genetic testing is recommended for all patients who have recurrent febrile seizures, both febrile and afebrile seizures, seizures beginning before the age of 1, or seizures triggered by vaccination before the age of 1. Detecting the genetic cause is very important for understanding the course of the disease and shaping the treatment. In this way we can better understand your child’s condition and evaluate possible future risks more accurately.

What Are the Long-Term Effects of Febrile Seizures?

Simple febrile seizures are generally benign and most children do not experience any long-term health problems as a result of this condition. However, some studies suggest that prolonged febrile seizures (febrile status epilepticus) may have a slight association with some long-term problems such as cognitive impairment, neuropsychiatric issues, and in very rare cases sudden unexpected death. However, the direct causal relationship and clinical significance of these findings are still being investigated.

In conclusion, febrile seizures, especially simple ones, are a common and usually harmless condition in childhood. The important thing is to remain calm when you encounter this situation, perform the correct intervention, and seek medical help when necessary. Remember that most children overcome this condition without problems and continue to grow up healthy. If you have any concerns or questions, do not hesitate to speak with your child’s doctor. I wish you healthy days.

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