MINNEAPOLIS, December 4, 2007—Children with autism seem less autistic when they are sick with a fever, according to new research published today in Pediatrics.

Kids experiencing fever showed fewer signs of hyperactivity, were more communicative, and were less irritable.

Anecdotal reports of improvements in autism symptoms related to fever have circulated for years, but this research, conducted at Baltimore's Kennedy Krieger Institute, is the first scientific investigation into the idea.

While kids with autism might be expected to be calmer and less hyperactive when they have fevers, the improvement in communication and socialization seen in the study suggests that fever directly affects brain function, pediatric neurologist Andrew Zimmerman, M.D., said in a report on WebMD. 

Zimmerman suggested that the observed improvement may mean that the underlying wiring of the brain of an autistic child is closer to normal than thought.

"Somehow, fever appears to be changing the ability to make these connections," Zimmerman told WebMD.

The study involved 30 children with autism spectrum disorders, including autism, who were observed by parents during and immediately after experiencing a fever of 100.4 degrees or greater, and seven days after being without fever.

The parents were asked to complete standardized behavior questionnaires during the three time points designed to assess behavior. Parents of children with autism spectrum disorders who did not experience fever were also surveyed at related time points.

More than 80 percent of the children with fever in the study showed some improvement in behavior during temperature elevations, the researchers reported in the December issue of the journal Pediatrics.

Web MD article