Fever is a common symptom in pediatrics, and some children have subsequent convulsive manifestations. What are the clinical signs that can indicate febrile convulsions? In which children is it likely to occur and what are the risks to the child? How should pediatricians deal with this disease and how should parents be reassured? In this edition of Medical Week, let’s get to know this seemingly scary, but good prognosis disease.
What are febrile convulsions?
Pediatric febrile convulsions (Febrile seizure, also known as febrile convulsions) are the most common type of neurological disorder in children, with a prevalence of 2-4% in children under 5 years of age. Because the central nervous system and thermoregulatory system are not yet well developed, children are prone to hyperthermia and can cause abnormal firing of the cerebral cortex in some children, resulting in convulsions. Fortunately, most simple febrile convulsions resolve on their own without structural damage to the nervous system or sequelae, and do not increase their risk of future epilepsy.
The American Academy of Pediatrics (AAP) revised guidelines in 2008 define febrile convulsions as epileptic seizures in febrile children 6 months to 5 years of age, excluding intracranial infections, metabolic disorders, and without a history of febrile convulsions. The fever temperature is usually 38°C or higher.
Febrile convulsions can be divided into two types: simple and complex. The simple type accounts for 80% of febrile convulsions and has a better prognosis than the complex type.
What kind of babies are prone to febrile convulsions?
The occurrence of febrile convulsions has different degrees of correlation with the febrile temperature, genetic factors, infections, and vaccination status of the child.
Fever: The higher the maximum body temperature of the child, the more likely febrile convulsions will occur, but the temperature threshold that triggers convulsions varies from person to person. Maximum body temperature is the main determinant of the occurrence of febrile convulsions.
Genetic factors: Although the mode of inheritance is not fully revealed, numerous studies have confirmed the existence of a genetic susceptibility to febrile convulsions in children with the onset of the disease, and its occurrence is influenced by several genes. A history of febrile convulsions in first-degree relatives or siblings increases the risk of febrile convulsions in children.
Infections: Children with febrile convulsions usually have a combination of viral and, in a few children, bacterial infections. Some viruses that can cause high fever, such as human herpes simplex virus and influenza viruses (especially influenza A virus), predispose infected children to febrile convulsions.
Vaccination: Vaccination against certain diseases may cause febrile convulsions, such as pertussis, tetanus, diphtheria, measles, mumps, and rubella, but the probability of such events is low and is related to the preparation of the vaccine, the age of vaccination, and the genetic susceptibility of the affected child.
Clinical manifestations of febrile convulsions
The most common symptom of simple febrile convulsions is generalized tonic-clonic seizures, which may involve the muscles of expression and respiration. Some children may also present with foaming at the mouth. Persistent eye opening and squinting suggest an ongoing epileptic seizure, while eye closure and deep breathing mark the end of the seizure. Most episodes of simple febrile convulsions last 3-4 minutes and may be followed by disturbance of consciousness, irritability, and drowsiness.
Complex febrile convulsions tend to occur in younger children and are more associated with abnormal neurological development. The duration of seizures is longer (≥15 minutes) and the chance of recurrence within 24 hours is greater. A small percentage of children may develop transient hemiparesis.
How are febrile seizures treated?
For febrile children with epileptic seizures, the first step is to exclude other neurological infections and organic diseases by detailed history and physical examination. The following treatments can be initiated after the diagnosis of febrile convulsions.
Emergency treatment: Since most simple febrile convulsions can resolve on their own, this group of children does not need treatment. For children with seizures lasting more than 5 minutes, benzodiazepines should be given as early as possible in the ambulance or emergency room. analogs to terminate the seizure. The earlier treatment is initiated, the shorter the duration of the seizure and the better the prognosis of the child.
The fever should be treated symptomatically and the child should be physically cooled. Antipyretics may also be applied to relieve the child’s discomfort, but their use does not reduce the risk of recurrent convulsions. In addition, the child’s respiratory and circulatory system should be closely monitored, and assisted ventilation should be given if necessary.
Children with simple febrile convulsions can be discharged after treatment, while children with complex convulsions need to be admitted for further observation depending on the speed of recovery and temperature.
Long-term treatment: Because up to 1/3 of children with febrile convulsions experience recurrences, parents may be prescribed home benzodiazepines such as diazepam rectal gel or midazolam nasal spray (both are equally effective). Physicians should educate parents on the use of both drugs and emphasize that medication should be given only if the child’s convulsion recurrence lasts longer than 5 minutes.
Prophylaxis: A large number of systematic reviews have shown that continuous/intermittent prophylactic administration of anticonvulsant, antipyretic medications does not reduce the recurrence rate of febrile convulsions. Considering the generally good prognosis of febrile convulsions, the side effects of anticonvulsant drugs on the central system of children far outweigh their benefits. Therefore, the AAP does not recommend prophylactic use of antipyretics or anticonvulsants in children with febrile convulsions.
Febrile convulsive seizures in children often cause great parental concern and panic, so physicians should do a good job of reassuring parents by suggesting the following explanations.
Impact: Febrile convulsions themselves generally do not cause damage to the child’s brain and do not affect the child’s brain development or IQ.
Prognosis: The prognosis for most febrile convulsions is good, and although the seizure scene may be frightening, the likelihood of death due to febrile convulsions is extremely low.
Seizure management: Parents should keep the child on their side, do not put foreign objects such as towels in their mouths, and do not forcefully stop the child’s limb from jerking. Take note of the duration of the seizure. A seizure lasting less than 5 minutes does not need to be treated. If it is longer than 5 minutes, call an ambulance for help. If you have benzodiazepines prescribed by your doctor at home, you can also give them at the prescribed dose if the seizure lasts longer than 5 minutes.
Treatment of fever: Help the child to dissipate heat by not overdressing or covering the child to avoid further increase in body temperature. Similarly, a systematic review of febrile convulsions published by the BMJ has discouraged the use of warm water to wipe the child’s body.
Recurrence: 1/3 of children are at risk for recurrent febrile convulsions, and parents should be prepared and monitor their child’s condition.