One of the scariest things for any parent to see is their child having a seizure. It comes on suddenly and seems to take over the child's body. Its victims often become unconscious and are thrown into a series of uncontrollable jerking movements. The eyes may move to one side or the other. The jaw tightens. Some people wet their pants.

The episode usually lasts a few seconds to a few minutes (but it can feel like hours) and then it's gone, leaving the child exhausted. Sleep often follows. It's hard for a parent to imagine any circumstance where this disturbing picture is completely harmless, but in the case of febrile seizures, it is.

Febrile is the medical term used to describe someone who has a fever, so febrile seizures are brought on by a fever and nothing else. They occur in children between the ages of 3 months and 5 years and 2-5 percent of all kids will have at least one febrile seizure by their fifth birthday. One out of every three children who has a febrile seizure will have at least one more before outgrowing them around age 5 or 6.

Why some kids get these and others don't is anybody's guess, but they do tend to run in families. A child who has a sibling with febrile seizures has a 10 percent chance of having them. If both a parent and a child had febrile seizures, then other children in that family have a 50 percent risk of having them. About 25 percent of children with febrile seizures have a close relative who had them as a child.

Febrile seizures are divided into "simple" or "complex," depending on how long the seizure lasts. Simple febrile seizures are the most common. They last less than 15 minutes (usually a lot less), involve the entire body and don't recur within 24 hours. Complex febrile seizures are ones that last more than 15 minutes, involve only a particular part of the body or occur more than once in 24 hours. Complex febrile seizures are a little concerning because they may represent a more serious condition, but usually not.  

The seizure itself is almost always harmless. Febrile seizures do not cause brain damage, decreased intelligence or lead to behavioral issues. The risk of epilepsy is slightly higher in children with a history of febrile seizures, especially complex ones, but it still remains pretty low.

The reason for the fever doesn't seem to matter, but since most kids get viruses several times a year, that's the most likely cause. Usually the child's temperature is greater than 102.2, although it can be lower. Some parents whose children have febrile seizures start fever-lowering medications like Tylenol or ibuprofen at the first sign of illness, but in many cases the seizure is the first sign.  

When a child has a febrile seizure, parents will almost always seek out their pediatrician or take the child to the Emergency Department. It is not unreasonable to call 911, but in most cases the seizure will be over long before they arrive. The first thing a doctor will do is try to make sure the seizure was caused by the fever and not something else. Once that's established, the source of the fever will be determined and treatment will be directed there. In some cases, that will mean antibiotics; in many cases it will not. Most childhood fevers are caused by viruses so fluids, rest and fever-lowering medication may be all that are needed.

Many parents wonder why all kids with febrile seizures aren't placed on anti-seizure medications (anti-convulsants) to try to avoid another episode. The fact is that every medication has risks and side effects. These have to be weighed against the risk of another seizure. Since two out of three children will only have one febrile seizure in their lifetime, the risks and side effects of treatment generally far outweigh the benefits.

For parents who just saw their child have a seizure, that may be hard to understand. But remember, even if a child does have a second febrile seizure, it is almost always brief and will not cause long-term problems.

There's no way to avoid febrile seizures if a child is predisposed to have one, but parents can be alert to rising temperatures, start fever-lowering medications right away (remember, never give aspirin to a child) and learn to take a temperature properly with the right thermometer. If your child does have a febrile seizure, it will be an upsetting experience, but it's a benign process and, aside from the anxiety they can cause, febrile seizures will eventually go away completely.

Dr. Lisa Thornton, a mother of three, is director of pediatric rehabilitation at Schwab Rehabilitation Hospital and LaRabida Children's Hospital. She also is assistant professor of pediatrics at the University of Chicago. E-mail her at drlisathornton@gmail.com.

Dr. Lisa Thornton, a mother of three, is director of pediatric rehabilitation at Schwab Rehabilitation Hospital and LaRabida Children’s Hospital. She also is assistant professor of pediatrics at the University of Chicago.

See more of Dr. Thornton's stories here.

Contact Dr. Thornton at drlisathornton@gmail.com

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