A febrile seizure is a neurological event that can be deeply alarming for parents, often occurring without warning in an otherwise healthy child. This type of seizure is directly related to a rise in body temperature, which triggers the convulsion. The rapid onset of shaking and unresponsiveness, especially when accompanied by a high fever, naturally leads to significant parental fear about the child’s immediate safety and long-term health. Understanding the nature of this common childhood occurrence is the first step in managing the anxiety it creates.
What Exactly Is a Febrile Seizure?
A febrile seizure is defined as a seizure occurring in a child between the ages of six months and five years that is associated with a fever of 100.4°F (38°C) or higher. This event is not caused by a central nervous system infection, such as meningitis, nor is it related to a prior history of afebrile seizures. Febrile seizures are considered the most common type of convulsive event in childhood, affecting approximately two to five percent of children in this age range.
They are caused by the developing brain’s temporary sensitivity to the effects of a fever. These convulsions usually involve generalized shaking and a loss of consciousness, though the specific movements can vary. The typical febrile seizure lasts for only a few seconds up to a few minutes, with the child returning to a state of confusion or sleepiness afterward.
The majority of these events are classified as “simple” febrile seizures, meaning they are generalized, last less than 15 minutes, and do not recur within a 24-hour period. A less common type, the “complex” febrile seizure, lasts longer than 15 minutes, involves focal features affecting only one side of the body, or occurs multiple times in a single day.
The Actual Risk of Mortality
Death from a simple febrile seizure is exceedingly rare. Simple febrile seizures are recognized as a benign and self-limiting event that does not lead to death or cause brain damage.
Research has analyzed long-term mortality following a febrile seizure, indicating that for children experiencing a simple febrile seizure, there is no significant increase in the rate of death. However, studies have identified a slightly increased mortality rate for children who experience complex febrile seizures, particularly during the first two years after the event. This elevated risk is generally attributed to a small subgroup of children who had pre-existing neurological abnormalities or who subsequently develop epilepsy.
Febrile status epilepticus is a rare complication where the seizure lasts longer than 30 minutes. This prolonged seizure is a medical emergency, but the overwhelming majority of children who experience a febrile seizure, whether simple or complex, make a complete recovery without any lasting consequences.
Immediate Steps During a Seizure
When a child is having a febrile seizure, the primary focus is protecting them from injury and ensuring their breathing remains unobstructed. Parents should gently place the child on the floor or a protected surface away from any sharp or hard objects. The child should be turned onto their side, into the recovery position, with their head tilted slightly backward to allow any saliva or vomit to drain out.
It is crucial to time the duration of the seizure, as this information is vital for medical providers. During the event, parents should follow these guidelines:
- Do not attempt to restrain the child’s movements.
- Never place anything into the child’s mouth, as this can cause injury.
- Do not attempt to give the child fever-reducing medication.
- Avoid trying to cool the child down with a cold bath.
Emergency medical services must be contacted immediately if the seizure lasts for five minutes or longer. Calling 911 is also necessary if the child has trouble breathing, their skin or lips turn blue, or they appear extremely lethargic and are not responding normally after the seizure stops. A child’s first febrile seizure should also prompt a visit to the emergency department to determine the source of the fever and rule out other causes.
Long-Term Outlook and Recurrence
The majority of children who have a febrile seizure will not experience any subsequent seizure events. However, the chance of a recurrence with a future fever is approximately 30 to 50 percent, with the risk being higher if the first seizure occurred before 18 months of age.
Having a simple febrile seizure only slightly increases a child’s risk of developing chronic epilepsy later in life. The risk of developing epilepsy is estimated to be about two percent following a simple febrile seizure, which is marginally higher than the general population risk of about one percent. This risk is elevated for children who experience complex febrile seizures or have an underlying developmental history.
The risk of having a febrile seizure disappears once a child reaches six years of age. For most children, these events remain isolated occurrences of early childhood without any measurable impact on their future health or neurological development. The focus of care remains on managing the underlying illness causing the fever.