OVERVIEW

What is febrile seizure? How many convulsions typically occur in febrile seizures?

Febrile seizure is a common neurological disorder in childhood, characterized by convulsions during episodes of elevated body temperature, hence it is also commonly referred to as "febrile convulsion."

It is most frequently seen in children aged 6 months to 5 years. Current research suggests that febrile seizures are related to a child's genetic predisposition as well as specific viral infections. They can be classified into simple febrile seizures and complex febrile seizures.

• Simple febrile seizure:

  • No recurrence within 24 hours after a single episode;

  • Each episode is brief, lasting no longer than 15 minutes;

  • Manifests as generalized muscle stiffness and symmetrical limb convulsions.

• Complex febrile seizure:

  • Episodes last longer than 15 minutes;

  • Convulsions involve asymmetrical limb movements, possibly affecting only one side of the body;

  • Recurrent seizures after the initial episode.

Simple febrile seizures are more common and have a good prognosis. Complex febrile seizures are rarer and carry a certain risk of progressing to afebrile seizures, i.e., epilepsy.

Can febrile seizures be cured?

Most cases can be cured.

The majority of febrile seizures are benign and do not cause long-term complications in children. Medication can quickly control the convulsions. A small number of patients with febrile seizures may experience recurrent episodes, and as they age, there is a possibility of developing afebrile seizures.

Do febrile seizures affect lifespan?

No, they do not affect a child's lifespan.

Do febrile seizures affect a child's intelligence?

No.

Febrile seizures do not impair a child's intelligence, and the likelihood of long-term neurological sequelae is very low. A UK clinical study tracking 381 children with febrile seizures found no difference in academic performance or developmental behavior indicators compared to healthy children by the age of 10.

Are febrile seizures common?

They are the most common neurological disorder in childhood.

The incidence rate is 2%–4% in children under 5 years old. Boys are more susceptible, with a male-to-female ratio of 1.6:1.

SYMPTOMS

What symptoms do children with febrile seizures typically have?

• The child experiences convulsions within 24 hours of developing a fever.

• There is an elevated body temperature during the seizure.

• The child's seizure may manifest as: eyes rolling upward or staring, not crying, no response when called by adults, bluish lips, foaming at the mouth, clenched fists, stiffening of arms and legs, continuous shaking of hands and feet, head tilting backward, or loss of bladder/bowel control.

• Not all of these symptoms necessarily occur. The most critical symptom is that during the seizure, the child appears dazed and does not cry or respond when called by adults.

CAUSES

What are the common causes of febrile seizures?

• Elevated body temperature: High fever is a key factor in triggering febrile seizures, with temperatures exceeding 38°C being a critical condition for convulsions.

• Specific viral infections:

  • Febrile seizures are not directly caused by viral infections but rather by the persistent high fever induced by the virus, which then triggers the seizure.

  • The likelihood of febrile seizures occurring alongside viral infections is relatively high.

  • Common viruses associated with febrile seizures include human herpesvirus, influenza virus, parainfluenza virus, and adenovirus.

• Genetic predisposition: Not all children experience seizures during high fever; it is related to their genetic makeup. Children with febrile seizures are believed to have specific genetic phenotypes. Febrile seizures often cluster in families, with a 10%–20% likelihood of relatives also experiencing them.

• Vaccination:

  • Fever is a common side effect of vaccinations. Certain vaccines, particularly live attenuated vaccines (e.g., MMR) and whole-cell vaccines (e.g., whole-cell pertussis vaccine), are more likely to trigger febrile seizures.
  • However, there is no evidence linking post-vaccination febrile seizures to long-term epilepsy. According to guidelines in most countries, febrile seizures are not a contraindication for vaccination.

At what age do febrile seizures most commonly occur?

Febrile seizures typically occur between 6 months and 5 years of age, with the peak incidence between 12 and 18 months.

DIAGNOSIS

What tests are needed to diagnose febrile seizures?

If febrile seizures are clinically diagnosed, no tests may be required.

However, for differential diagnosis, the following tests may be necessary: complete blood count (CBC), C-reactive protein (CRP), head CT or MRI, electroencephalogram (EEG), cerebrospinal fluid examination, blood biochemical tests, metabolic screening, bacterial culture, etc.

Why are these tests performed for febrile seizures?

• CBC, CRP, bacterial culture: Help determine whether there are signs of bacterial infection.

• Biochemical tests: Assess overall health, evaluate liver and kidney function, and check electrolyte levels. If abnormalities are found, further metabolic screening may be required.

• Head CT or MRI: Examine brain structure and rule out developmental abnormalities.

• EEG: Evaluate brain function.

• Cerebrospinal fluid examination: If symptoms and physical examination suggest bacterial meningitis, this test is needed to rule it out.

What are the complications of febrile seizures?

If it is a complex febrile seizure, the child may develop afebrile seizures (epilepsy) as they grow older.

TREATMENT

Which department should be consulted for febrile seizures?

During a seizure, go to the emergency department (pediatrics). Follow-up care will be managed by pediatric internal medicine or pediatric neurology.

How should febrile seizures be treated?

If the child is in a convulsive state, sedative medication should be used to relieve the seizure. At the same time, identify the cause of the fever, control body temperature, and prevent recurrent high fever.

Additionally, neurological symptoms should be evaluated to rule out seizures caused by bacterial meningitis or metabolic disorders before diagnosing febrile seizures.

What should parents do if their child has a febrile seizure?

When a child experiences a febrile seizure, parents should stay calm. Most febrile seizures do not cause harm to the child. Take the following steps:

• Loosen the child's clothing to help dissipate heat.

• Lay the child flat, turn their head to the side, or place them in a side-lying position, and wait for the seizure to end. In most cases, seizures stop on their own within 5 minutes.

• After the child regains consciousness, oral fever-reducing medication can be given.

• Since it is impossible to predict how long the seizure will last, medical intervention is needed if it exceeds 5 minutes. Stay calm, ensure the child is in a safe position, and call 120 or take them to the hospital.

• Especially if the seizure does not stop after 2–3 minutes (since seizures lasting over 5 minutes require medication).

• Or if severe symptoms occur during the seizure (difficulty breathing, choking on a foreign object, persistent or repeated cyanosis).

• Depending on the location, arrange immediate transportation to the nearest hospital by car, taxi, or ambulance (120).

Avoid the following actions:

• Pressing the philtrum, acupuncture, or burning acupoints.

• Restraining the child's limbs.

• Wrapping the child in thick blankets.

• Forcing objects like spoons, sticks, or fingers into the child's mouth.

These practices may harm the child and provide no benefit to their condition.

Do children with febrile seizures need follow-up after discharge?

Yes.

Follow-up visits should monitor the child's development. If the child experiences recurrent febrile seizures or has complex febrile seizures, an EEG follow-up may be necessary.

DIET & LIFESTYLE

What should children with febrile seizures pay attention to in their diet?

Normal diet is sufficient, as febrile seizures are not related to food types. A healthy and balanced diet benefits the child's overall health.

What should children with febrile seizures pay attention to in daily life?

No special precautions are needed in daily life—maintaining a healthy lifestyle is sufficient.

Engage in appropriate outdoor activities and exercise to strengthen physical fitness.

Practice good hand hygiene, wash hands frequently, prevent cross-infection, and reduce the chances of illness and fever.

PREVENTION

How to Prevent Febrile Seizures?

• Some evidence suggests that for children with frequent seizures in a short period, status epilepticus requiring anticonvulsant medication to terminate the episode, or extremely anxious parents, diazepam may be recommended orally during fever to reduce the likelihood of convulsions.

• Before the flu season, getting a flu vaccine can reduce the chance of high fever caused by influenza, thereby lowering the incidence of febrile seizures.

• Receiving the rotavirus vaccine can reduce or alleviate diarrhea in autumn and winter, decreasing the risk of seizures triggered by enterovirus infections.

• When family members are sick, wearing masks and washing hands before contact with children can reduce the chance of cross-infection.