What are the diagnostic criteria for a febrile (fever-induced) convulsion?

From the Guidelines

A febrile convulsion is diagnosed when a child between 6 and 60 months of age experiences a seizure associated with a fever without evidence of central nervous system infection or inflammation, with simple febrile seizures lasting less than 15 minutes, being generalized, and occurring once in a 24-hour period 1. The diagnostic criteria for febrile convulsion include:

• Age: 6 to 60 months
• Fever: presence of fever without evidence of central nervous system infection or inflammation
• Seizure characteristics: generalized, lasting less than 15 minutes, and occurring once in a 24-hour period for simple febrile seizures
• Exclusion of other causes: meningitis, encephalitis, electrolyte abnormalities, or underlying epilepsy must be excluded The American Academy of Pediatrics defines simple febrile seizures as brief (<15-minute) generalized seizures that occur once during a 24-hour period in a febrile child who does not have an intracranial infection, metabolic disturbance, or history of afebrile seizures 1. The diagnosis of febrile seizure is based on the presence of a fever and a seizure, with the exclusion of other causes of seizures, and the classification into simple or complex febrile seizures based on the duration, recurrence, and focal features of the seizure 1. Key points to consider in the diagnosis and management of febrile seizures include:
• The risk of developing epilepsy in children with simple febrile seizures is extremely low, although slightly higher than that in the general population 1
• Antipyretics have been shown to be ineffective in preventing recurrent febrile seizures, and continuous anticonvulsant therapy with phenobarbital, primidone, or valproic acid and intermittent therapy with diazepam are effective in reducing febrile-seizure recurrence, but the potential toxicities associated with these agents outweigh the relatively minor risks associated with simple febrile seizures 1
• Most febrile seizures are benign and self-limiting, requiring no specific treatment beyond fever management with acetaminophen or ibuprofen.

From the Research

Diagnostic Criteria for Febrile Convulsion

The diagnostic criteria for febrile convulsion include:

• Convulsion associated with fever in an infant or child aged between six months and six years 2
• The febrile illness causing the convulsion should not be secondary to an intracranial infection (meningitis or encephalitis) or acute electrolyte imbalance 2, 3
• Exclusion of underlying meningitis in all children with febrile seizures, either clinically or by lumbar puncture if any doubt remains 3

Key Considerations in Diagnosis

• The cause of the fever should be identified and treated specifically 3
• Consideration of other potential causes of seizures, such as infection, head trauma, intoxication, electrolyte imbalance, low blood sugar, or phakomatoses 3
• Possibility of epilepsy, where fever has triggered a seizure recurrence in a child who also experiences unprovoked seizures 3

Investigation and Management

• Diagnosis is based mainly on history taking, and further investigations are not generally needed in fully immunised children presenting with simple febrile convulsions 4
• Treatment involves symptom control and treating the cause of the fever 4
• Antipyretic agents, such as acetaminophen and ibuprofen, may be used to reduce fever, but their effectiveness in preventing febrile seizures is limited 5, 6