Febrile seizures

Febrile seizures | NHS inform Home Illnesses and conditions Symptoms and self-help Tests and treatments Healthy living Care, support and rights Scotlands Service Directory 0 Home Illnesses and conditions Brain, nerves and spinal cord Febrile seizures Febrile seizures About febrile seizures Symptoms of febrile seizures Causes of febrile seizures Diagnosing febrile seizures Treating febrile seizures About febrile seizures A febrile seizure is a fit that can happen when a child has a fever. Febrile seizures are also sometimes called febrile convulsions. They are relatively common and, in most cases, arent serious. Around one in 20 children will have at least one febrile seizure at some point. They most often occurbetween the ages of six months and three years. During a febrile seizure, the childs body usually becomes stiff, they lose consciousness and their arms and legs twitch. Some children may wet themselves. This is known as a tonic clonic seizure. Read more about the symptoms of febrile seizures What to do during a seizure If your child is having a febrile seizure, place them in the recovery position . Lay them on their side, on a soft surface, with their face turned to one side. This will stop them swallowing any vomit, keep their airway open and help prevent injury. Stay withyour childand try to make a note of how long the seizure lasts. If its your childs first seizure, or it lasts longer than five minutes,take them to the nearest hospital as soon as possible, or dial 999 for an ambulance. While its unlikely that theres anything seriously wrong,its best to be sure. Ifyour child has hadfebrile seizuresbefore and the seizure lasts for less than five minutes, phone your GP or the NHS 24 111 service for advice. Dont put anything, including medication,in your childs mouth during a seizure because theres a slight chance thatthey might bite their tongue. Almost all children make a complete recovery after having a febrile seizure. Read more about diagnosing febrile seizures and treating febrile seizures Types of febrile seizure There are two main types of febrile seizure. Simple febrile seizure A simple febrile seizure is the most common type of febrile seizure, accounting for about eight out of 10 cases. Its a fit that: is a tonic clonic seizure (see above) lasts less than 15 minutes doesnt reoccur within 24 hours or the period in which your child has an illness Complex febrile seizure Complex febrile seizures are less common, accounting for two out of 10 cases. A complex febrile seizure is any seizure that has one or more of the following features: the seizure lasts longer than 15 minutes your child only has symptoms in one part of their body (this is known as a partial or focal seizure) your child has another seizure within 24 hours of the first seizure, or during the same periodof illness your child doesnt fully recover from the seizure within one hour Why febrile seizures occur The cause of febrile seizures is unknown, although theyre linked to the start of a fever (a high temperature of 38C (100.4F) or above). In most cases, a high temperature is caused by an infection such as: chickenpox flu (influenza) middle ear infections (otitis media) tonsillitis There may also be a genetic link to febrile seizures because the chances of having a seizure are increased if a close family member has a history of them. Around one in four children affected by febrile seizures has a family history of the condition. Read more about the causes of febrile seizures Complications Febrile seizures have been linked to an increased risk of epilepsy , as well as other problems. Recent research findings may indicate a link between febrile seizures and sudden unexplained death in childhood (SUDC), possibly due to the connection between febrile seizures and epilepsy. However, this link hasnt been proven and SUDC is incredibly rare, affecting around one in 100,000 children which is equivalent to a 0.001% chance. In addition, one of the biggest studies of its kind looked at more than 1.5 million children with a history of febrile seizures and found no evidence of an increased risk of death in later childhood or adulthood. Febrile seizures and epilepsy Many parents worry that if their child has one or more febrile seizures, theyll develop epilepsy when they get older. Epilepsy is a condition where a person has repeated seizures without fever. While its true that children who have a history of febrile seizures have an increased risk of developing epilepsy, it should be stressed that the risk is still small. Its estimated that children with a history of simple febrile seizures have a one in 50 chance of developing epilepsy in later life. Children with a history of complex febrile seizures have a one in 20 chance of developing epilepsy in later life. This is compared to around a one in 100 chance for people who havent had febrile seizures. Symptoms of febrile seizures The main symptom of a febrile seizure is a fit that occurs while a child has a fever. Febrile seizures often occur during the first day of a fever, which is defined as a high temperature of 38C (100.4F) or above. However, there appears to be no connection between the extent of your childs fever and the start of a seizure. Seizures can occur even if your child has a mild fever. Simple febrile seizures canhappen when theres a rapid rise in temperatureand you may only realise your child is ill when they have a fit.Alternatively,they can occur as your childs temperature drops from a high level. During simple febrile seizures: your childs body will become stiff and their arms and legs will begin to twitch theyll lose consciousness and they may wet or soil themselves theymay also vomit and foam at the mouth and their eyes may roll back the seizure usually lasts for less than five minutes following the seizure, your child may be sleepy for up to an hour afterwards Complex febrile seizures tend to last longer than 15 minutes, and the symptoms may only affect one area of your childs body. The seizure sometimes recurs within 24 hours or during the period in which your child is ill. Seeking medical advice You should take your child to hospital or dial 999 for an ambulance if: your child is having a fit for the first time the seizure lasts longer than five minutes andshows no signs of stopping you suspect the seizure is being caused by another serious illness, for example meningitis your child is having breathing difficulties If your child has previously had febrile seizures, its recommended that you telephone your GP or call the NHS 24 111 service for advice. You should also contact your GP or the NHS 24 111 service if your child shows signs and symptoms ofdehydration (a lack of fluid in the body). This includes: a dry mouth sunken eyes a lack of tears when crying a sunken fontanelle  the soft spot usually found at the top of a young childs head Causes of febrile seizures Febrile seizures are linked to fevers, but the exact cause is unknown. Some researchers think that the biological processes associated with a high temperature may be responsible. A high temperature is thought to be caused by a bacterial or viral infection that stimulates the release of cytokines. Cytokines are proteins that affect the parts of the brain and nervous system responsible for regulating the bodys temperature. Their release causes a rise in the bodys temperature. One theory is that in certain people, high levels of cytokines may temporarily scramble the workings of the brain and nervous system, triggering a seizure. Family history Althoughfebrile seizures are poorly understood, a family history of the conditions is thought to increase the risk. If a child has a first-degree relative (mother, father, sister or brother) with a history of febrile seizures, their risk of having seizures increases. The more relatives affected, the higher the risk. This is probably the result of one or more genetic mutations that a child inherits from their parents, which makes them more susceptible to seizures. A genetic mutation means the instructions carried in certain genesbecome scrambled, resulting in some of the bodys processes not working in the normal way. Associated infections Most febrile seizures occur whena child has a high temperature caused by an infection. The three most common infections associated with febrile convulsions are: viral infections, such as chickenpox and flu middle ear infections (otitis media) tonsillitis Other infections associated with febrile seizures are: urinary tract infections(UTIs) upperrespiratory tract infection an infection of the mouth, nose and throat, and associated tissues and structures gastroenteritis  an infection of the digestive system lower respiratory tract infections, such as pneumonia (a lung infection) and bronchitis (an infection of the airways that supply the lungs) Vaccinations In rare cases, febrile seizures can occur after a child has a vaccination. Research has shown that your child has a one in 3,000 to 4,000 chance of having a febrile seizure after having the MMR vaccine . The risks are even lower with the DTaP/IPV/Hib vaccine  a one in 11,000 to 16,000. Diagnosing febrile seizures Febrile seizures can often be diagnosed from a description of what happened. Further tests may be needed if the cause of the associated infection isnt clear. Its unlikely that your doctorwill see the seizure, so an account of what happenedis useful. Its useful to know: how long the seizure lasted what happened  body stiffening, twitching of the face, arms and legs, staring and loss of consciousness whether your child recovered within one hour whether theyve had a seizure before Tests to identify the source of the infection will only usually be necessary to rule out rarer conditions which can cause similar symptoms, such as meningitis . A blood or urine sample may be needed to test for signs of infection. It can sometimes be difficult to obtain a urine sample from young children, so it may have to be done in hospital. Read more about blood tests Further tests Further tests may be carried out in hospital if your childs symptoms are unusual  for example, if they dont have a high temperature or their seizures dont follow the normal pattern. Further testing and observation in hospital is also usually recommended if your child is having complex febrile seizures . Your child may have other tests including an electroencephalogram and lumbar puncture, particularly if theyre less than 12 months old. These two testsare explained below. Electroencephalogram Anelectroencephalogram (EEG) measures your childs electrical brain activity through electrodes that are placed on their scalp. Unusual patterns of brain activity can sometimes indicate epilepsy . However, some studies have suggested that an EEG may not be useful in many cases of febrile seizures. Lumbar puncture During a lumbar puncture , a small sample of cerebrospinal fluid (CSF) is removed for testing. CSF is a clear fluid that surrounds and protects the brain and spinal cord. A hollow needle is inserted into the base of the spine to obtain the CSF sample. During the procedure, local anaesthetic will be used to numb your childs back so that they dont feel any pain. A lumbar puncture can be used to determine whether your child has an infection of the brain or nervous system. Treating febrile seizures In many cases, febrile seizures do not need to be treated, although care should be taken to deal with a seizure as it happens. What to do during a seizure If your child is having a febrile seizure, place them in the recovery position . Lay them on their side, on a soft surface, with their face turned to one side. This will stop them swallowing any vomit, and will keep their airway open and help prevent injury. Stay with your child while theyre having a seizure, and make a note of when the seizure started to keep track of how long it lasts. If the seizure lasts for less than five minutes, phone your GP or call the NHS 24 111 service. If its your childs first seizure, or if it lasts longer than five minutes,take your child to the nearest hospital as soon as possible. While theres probably nothing seriously wrong with your child, its best to be sure. Dont put anything, including medication,in your childs mouth while theyre having a seizure. Theres a slight chance that they might bite their tongue, although any damage isnt usually serious and will heal within a few days. Trying to stop someone biting their tongue by placing your hand or an object in their mouth could be dangerous both for you and forthem. High temperature (fever) Reducing a high temperature can help make your child feel more comfortable. Paracetamol and ibuprofen have been shown to be effective in reducing a high temperature. However, they wont reduce thechances of your child actually having a seizure. Removing any unnecessary clothes and bedding will also help to lower your childs temperature. Aspirin should never be given to childrenunder 16 years of age because theres a small risk that the medication could trigger a condition called Reyes syndrome, which can cause brain and liver damage. The use of cold sponges or fans isnt recommended for treating a high temperature. Theres little evidence that theyre effective, and they may cause your child discomfort. Your GP will be able to give you additional advice about treating the underlying cause of your childs high temperature. Its also important to prevent dehydration during a fever by making sure your child drinks plenty of fluids. Recurring febrile seizures About one third of children will have a febrile seizure again during a subsequent infection. This often occurs within a year of the first febrile seizure. Recurrence is more likely if: the first febrile seizure occurred before your child was 18 months old theres a history of seizures or epilepsy in your family before having the first seizure your child had a fever that lasted less than onehour or their temperature was less than 40C (104F) your child has multiple seizures during the same febrile episode ( complex febrile seizure ) your child attends a day care nursery (this increases their chances of developing common childhood infections, such as the flu or chickenpox ) Itsnot recommended that your child is given a prescription of regular medicines to prevent further febrile seizures. This is because the adverse side effects associated with many medicines outweigh any risksof the seizures themselves. Research has shown that the use of medication to control feverisnt likely to prevent recurrence of further febrile seizures. However, there may be exceptional circumstances where medication to prevent recurrent febrile seizures is recommended. For example, children may need medication if they have a low threshold for having seizures during illness, particularly if the seizures are prolonged. In this case, your child may be prescribed medications such as diazepam or lorazepam to take at the start of a fever. Children whove had a febrile seizure following a routine vaccination (which is very rare), are no more at risk of having another seizure compared to children whove had a seizure due to another cause for fever. Source: NHS 24 - Opens in new browser window Last updated: 07 March 2024 How can we improve this page? Help us improve NHS inform Thank You Your feedback has been received Dont include personal information e.g. name, location or any personal health conditions. 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