Halloween can be a scary time for parents of kids with food allergies. This year, things will be much different for Christine Cassen, a North Texas mom of two daughters with severe peanut allergies.

"It's a big relief not having to worry about something really serious happening on Halloween," said Cassen, a producer at WFAA.

For years, Halloween cast a shadow as Cassen's worst nightmare. Her daughter Emma once had such a terrible allergic reaction to a piece of candy that she had to be rushed to the hospital.

"This year, we won't have to worry about that," said Cassen.

In March, Cassen and her husband took a shot on a treatment for their daughters called food oral immunotherapy (OIT). Emma and sister Chloe ate measured amounts of peanuts every day. At first, they ingested almost trace amounts of peanut protein under the watchful eye of doctors, who gradually increased the dose as long as the girls experienced no extreme negative reaction.

"We've had no problems," said Cassen. "I mean we've had some hives here and there, but it's been very easy. And I'm on a lot of the Facebook groups so I see what other people go through. We're very fortunate. Some people, it's just a very easy smooth journey and for other people it's not."

WFAA followed the girls to several doctors visits at Medical City Children's Hospital. Their final test came in October when they were scheduled to scarf down 24 peanuts -- twice the amount they've ever eaten.

"Then we set this timer for 45 minutes and we wait here just to make sure that they don't have any kind of reaction," explained Cassen as she measured peanuts for her daughters.

The last six months of therapy all came down to what happened in those final moments. And it was good news. Both girls passed the test of tolerance.

"The real transformation starts today," said Cassen wearing a huge smile of relief. "One less thing to worry about."

"That's the biggest thing," said Joanna Rolen, the physician's assistant who was monitoring Chloe and Emma. "They're now safe. They can go to birthday parties, pool parties... sleepovers -- without there being a fear that mom has to check with what food are they going to have, or they have to bring their own."

For Cassen, a once spooky holiday is now something the whole family can look forward to -- the tricks and the treats.

"I'm very excited about that. It's going to be very different," said Cassen. "They'll be able to eat all the candy they get for the first time ever."

Experts said that since the girls are considered graduates of their OIT program, they can freely eat peanuts in any form they like. But they must eat at least eight peanuts every day for now.

Doctors will continue to monitor them and their dosing could change after a few years to less than that.

Also, Chloe and Emma will still require a rest period after they eat anything with the equivalent to eight peanuts in it. That means two hours after consumption with no running around because that could trigger a reaction in their bodies. For anything consumed that includes less than eight peanuts, they should be fine to run and play.