Febrile convulsions are a relatively common condition in young children with fever, with an age of onset of 6 months to 5 years (peak incidence is 18-22 months) and a slightly higher incidence in boys (60%).
At present, two main causes of febrile convulsions are thought to occur.
One, genetic qualities are associated; children with a history of febrile convulsions in their immediate family are more likely to have febrile convulsions, and children with a history of febrile convulsions in siblings or parents are four to five times more likely to have febrile convulsions than the general population.
Secondly, the immaturity of the nervous system in young children, the imperfection of thermoregulatory mechanisms and the abnormal energy metabolism of brain cells during the rise in body temperature are also involved in the pathogenesis.
As children grow older and their nervous systems mature, the probability of febrile convulsions decreases considerably. Most illnesses have a causal factor in addition to the cause. You would have guessed from the name ‘febrile convulsions’ that the cause of the illness is fever.
Statistically, these fevers can have a number of causes, including infectious (88%) and non-infectious fevers (12%).
Infectious fevers are commonly associated with viral infections and causes include acute upper respiratory tract infections or acute laryngitis (38%), otitis media (23%), pneumonia (15%), gastroenteritis (7%) and early childhood emergency rash (5%).
It is also important to note that fever may occur after vaccination against diphtheria, pertussis, measles and tetanus.