Scarlet fever is a disease many people thought disappeared a century ago, but it's still around, as one family discovered, and doctors say it needs to be treated quickly.

6- year-old William Gentry is feeling better now, but a few days ago the little boy says he was very sick.

"I didn't have my superpowers and I didn't feel really good," says William.

Sarah Perrone, William’s mom was right. Doctors told her William has scarlet fever.

"My mommy senses kicked in and I thought there is something else going on here," says Perrone. "People were generally surprised I think everybody took a step back for a second."

"Back in the 1800's people used to die from scarlet fever," says pediatrician Dr. Carolyn Clear.

William's pediatrician Dr. Carolyn clear says even though scarlet fever never went away it's become much easier to treat because of antibiotics.

"Basically what it is, is strep throat with a rash," says Dr. Clear.

The red bumpy, rash is caused by toxins released by the strep bacteria.

"It's a very sand papery feel and it usually starts on the neck and the chest and the belly and spreads to the arms and the legs," says Dr. Clear.

Other symptoms include: sore throat, headache, fever, fatigue and body aches. If you suspect your child has it, they need to see a doctor.

"If it's not treated it can turn into something called rheumatic fever which can then lead to rheumatic heart disease," says Dr. Clear.

That can cause serious heart problems later in life.

William is already back to school and playing baseball but his mom is determined to make sure this old fashioned sounding disease isn't ignored.

"Take them to the pediatrician when your senses kick in and you think this is more than just a sore throat," says Perrone.

(Information courtesy NBC News)