Not long ago my work-place had a seminar with an RN on seizures, since several of the childen in our programs have a history of them. When we were hearing about fever-induced seizures, the RN made a remark about how “of course you know high fevers are less serious in children than adults, until they reach 103/4 degree mark.” I’ve heard that, true, but what makes high fevers more serious in adults?
This is just my opinion, a WAG.
I don’t think a fever per se is any more serious in an adult than a kid. In fact, as you note, fevers are more likely to cause seizures in kids than in adults.
My hunch is that fevers in kids are usually due to benign things like viruses (usually benign). But adults have been exposed to many virsues over their lives and have become immune to many (?most) of them. Further, adults are probably less likely to get exposed to new viruses in any case since they’re not as intimate with as many other adults as little kids are with other kids (i.e. adults are more sanitary). So, if an adult has a fever, he/she’s more likely to be suffering from a non-viral infection than a kid with a similar fever. Generally, non-viral infections (such as bacterial infections) are more serious than viral infections. (And, fever can be due to other nasty things too - cancer, serious inflammation, etc. Such conditions are more common in adults)
So, it’s not that fevers are more serious in adults, it’s just that they’re more likely to be due to a serious cause.
It is a fact that children can endure higher fevers than adults without devastating neurological sequelae. Why this is so is open to debate.
Kids often are seen with fevers of 105F, who recover just fine. An adult who experiences such a fever often winds up neurologically “fried.” It may be due to the relative plasticity of the immature CNS, or it may be due to the specific insults that cause fever in adults and children.
But them’s is the facts.