ABC of one to seven. Febrile convulsions.

Abstract

Definition A febrile convulsion is a fit occurring in a child aged from 6 months to 5 years, precipitated by fever arising from infection outside the nervous system in a child who is otherwise neurologically normal. Convulsions with fever include any convulsion in a child of any age with fever of any cause. Among children who have convulsions with fever are those with pyogenic or viral meningitis, encephalitis, or cerebral palsy with intercurrent infections. Children who have a prolonged fit or who have not completely recovered within one hour should be suspected of having one of these conditions. Most of the fits that occur between the ages of 6 months and 5 years are simple febrile convulsions and have an excellent prognosis. If there is no fever the possibility of epilepsy should be considered. Often fever is recognised only when a convulsion has already occurred. An abrupt rise in temperature rather than a high level is important. There may be a frightened cry followed by abrupt loss of consciousness with muscular rigidity, which form the tonic stage. Cessation of respiratory movements and incontinence ofurine and faeces may occur during this stage, which usually lasts up to half a minute. The clonic stage which follows consists of repetitive movements of the limbs or face. By arbitrary definition, in simple febrile convulsions the fit lasts less than 20 minutes, there are no focal features, and the child is aged between 6 months and 5 years and has been developing normally. Rigors may occur in any acute febrile illness, but there is no loss of consciousness. Emergency treatment Nursing position to avoid vomiting with aspiration. If the child has fever all his clothes should be removed and he should be covered with a sheet only. The child should be nursed on his side or prone with his head to one side because vomiting with aspiration is a constant hazard. Rectal diazepam (0 5 mg/kg) produces an effective blood concentration of anticonvulsant within 10 minutes. The most convenient preparation resembles a toothpaste tube (Stesolid). Early admission to hospital or transfer to the intensive care unit should be considered if a second dose of anticonvulsant is needed. All children who have had a first febrile convulsion should be admitted to hospital to exclude meningitis and to educate the parents, as many fear that their child is dying during the fit. Physical examination at this stage usually does not show a cause for the fever, but a specimen of urine should be examined in the laboratory to exclude infection and glucose stick testing should be performed. Most of these children have a generalised viral infection with viraemia. A febrile convulsion may occur in roseola at the onset and three days later the rash appears. Occasionally acute otitis media is present, in which case an antibiotic is indicated, but most children with febrile convulsions do not need an antibiotic.