Febrile seizures: symptoms, what to do and when to call 999

The NHS says the child may become stiff and twitch, shake or have jerking movements, become unconscious, not respond or look at you when you talk to them, be sick or wet themselves, and be sleepy, irritable or confused for up to an hour afterwards. NHS inform also mentions foaming at the mouth and eyes rolling back.

Febrile seizures commonly come with an infection. NHS inform lists chickenpox, flu, middle ear infections, tonsillitis and urinary tract infections as examples, notes that a seizure can also occur when temperature drops from a high level, that a family history may increase the chance, and that in rare cases a seizure follows a vaccination.

The NHS says febrile seizures usually last for 2 to 3 minutes and that it is rare for them to last more than 10 minutes. NICE CKS defines a simple febrile seizure as one lasting less than 15 minutes with complete recovery within an hour. The NHS says a child may be sleepy, irritable or confused for up to 1 hour afterwards.

The NHS advises calling 999 or going to A&E if a seizure lasts more than 5 minutes, or if the child is more sleepy than usual for more than 1 hour after the seizure stops.

The NHS advises noting when the seizure starts and ends, protecting the head with your hands or something soft, removing dangerous objects nearby, and afterwards putting the child in the recovery position and making sure nothing in the mouth or throat affects breathing. NHS inform describes the recovery position as lying the child on their side on a soft surface with the face turned to one side.

The NHS says not to move the child or hold them in place, not to put anything in the mouth, and not to try to lower the temperature by undressing the child or sponging with cold water during the seizure. NHS inform also says never to put medication in the mouth during a seizure. After the seizure, NHS inform says children's paracetamol or ibuprofen can make a child more comfortable, that fluids are important, and that removing unnecessary clothing and bedding may help.

The NHS lists these reasons to call 999 or go to A&E: it is the first time the child has had a seizure; it lasts more than 5 minutes; the child has difficulty breathing; there is stiffness and twitching on one side only; the child is sleepier than usual for more than 1 hour afterwards; or there is more than one seizure within 24 hours. It adds that a child who is still seizing or unconscious should not be driven to A&E, and that 999 should be called instead.

NHS inform suggests phoning 111 if the child has had febrile seizures before, the seizure lasted less than 5 minutes, or there are signs of dehydration such as sunken eyes, dry mouth or no tears. NICE CKS lists meningitis and encephalitis as the serious causes that must be considered when assessing a seizure with fever, which is one reason a first seizure is always assessed medically.

A febrile seizure, also called a febrile convulsion or fit, is a seizure that happens when a child has a high temperature. NICE CKS defines it as a seizure with a temperature above 38 degrees in a child aged 6 months to 5 years, without infection of the central nervous system, and says it is the most common form of childhood seizure up to the age of 5.

NHS inform explains that the seizure is linked to a rise in temperature, although it is not known exactly what causes them. It also says that there is no connection between how high the fever is and whether a seizure starts, and that seizures can happen with a mild fever. They often occur during the first day of a fever.

Doctors divide febrile seizures into two groups. NICE CKS describes a simple febrile seizure as an isolated, generalised tonic-clonic seizure lasting less than 15 minutes that does not recur within 24 hours or within the same illness, with complete recovery within an hour. A complex febrile seizure has one or more of the following: a focal seizure affecting one side or one limb, duration over 15 minutes, recurrence within 24 hours or within the same illness, or incomplete recovery within an hour.

The distinction matters because complex seizures are more likely to prompt further assessment. NHS inform says children who have had complex febrile seizures have a small chance of developing epilepsy.

The NHS says a child will need to be checked in hospital after a first febrile seizure and may stay for a short time. Tests may include blood tests, a urine test and, in some cases, a lumbar puncture. NICE CKS says assessment looks for red flag symptoms, the underlying cause of the fever, the onset and peak of the temperature, the nature of the seizure and any drowsiness afterwards, previous seizures and family history, and examines the child for temperature, consciousness, neurological signs and hydration.

NICE CKS recommends immediate paediatric assessment for a first febrile seizure, for a child under 18 months, for complex seizures, where the cause of the fever is unclear, or where parents are very anxious or struggling to cope. Most febrile seizures need no specific treatment, according to the NHS, other than treating any infection.

NICE CKS says about a third of children have further febrile seizures after a first one. The NHS says very rarely a child keeps having them, in which case a doctor may prescribe a medicine to give during a seizure, with instructions. The NHS also says febrile seizures cannot be prevented, and NICE CKS says that antipyretics and anti-epileptic drugs are not routinely prescribed to prevent them unless on specialist advice.

On epilepsy, the NHS says febrile seizures are not epilepsy and that the chance of later epilepsy is slightly increased but rare. NICE CKS also advises parents about the generally benign nature of febrile seizures, support sources and making sure childhood immunisations are completed.

The first febrile seizure is almost always an NHS emergency matter: an ambulance or A&E, assessment by a paediatric team and, if well and recovered, discharge with advice. Because the cause of the fever has to be identified and serious infection excluded, this is not a situation for waiting for a routine appointment.

Families who have a child with repeated or complex seizures may later see a paediatrician or paediatric neurologist, on the NHS or privately, to discuss rescue medication, whether an EEG is needed or whether there is a neurodevelopmental concern. NICE CKS says referral is arranged for children with neurodevelopmental delay or signs of a neurocutaneous or metabolic disorder. The urgent pathway itself does not differ.