I will never enjoy a Snickers bar. Or a Reese’s Peanut Butter Cup. Or a PB&J.

According to Food Allergy Research and Education, 15 million Americans have food allergies, and I’m one of them.

My official allergy diagnosis, as last known, showed I’m allergic to peanuts, almonds, hazelnuts and Brazil nuts (whether or not I’ve ever even seen a Brazil nut is still questionable, but hey, knowledge is power). I can eat pecans, pistachios, cashews and walnuts. However, updates in the science behind allergies since my initial diagnosis shows the laundry list of nuts I can’t eat may have been preventable had I been exposed to these foods sooner.

I was diagnosed with a peanut allergy around the age of 3, when I had a minor reaction to peanut butter crackers my baby-sitter fed me. My parents had previously tried to feed me peanuts, though I’d refused to eat them. At the time, during the mid-1990s, this method of exposing toddlers to allergens was unusual.

“In the past for a while, we thought avoiding exposure until later years would reduce the risk of allergies,” said Dr. Kenneth Backman, chief of the allergy section at Bridgeport Hospital and president of Allergy & Asthma Care of Fairfield County. “We were telling families with a history of allergies to avoid those foods until the kids were 2 or 3. Turns out now it probably increases the risk of allergies. That early exposure may help prevent the onset of food allergies. Delaying introduction is the wrong approach.”

I certainly came from a family with a history of allergies, with my grandmother also allergic to nuts and my mom having eczema, which Backman said can be an indicator of food allergies. He said it’s now recommended children be exposed to allergens between 6 months and 1 year old.

Growing up, I avoided all nuts at my doctor’s recommendation. This included not only peanuts, but almonds, cashews, pecans, pistachios — basically anything vaguely nut, including coconuts, for no apparent reason. My assumption was I’d also been diagnosed as allergic to those nuts as well.

It turns out I was not the only one making assumptions. When I was 21, I decided it was time to put my allergies to the test, literally. I underwent scratch testing and blood testing to see if my allergies still stood from my previous testing 18 years earlier.

My scratch test results brought back several surprises, including the realization I’m allergic to some breeds of dogs and dust mites. (Is anyone not allergic to dust mites?) It also showed I had only minor reactions to some tree nuts.

To investigate that further, I had blood testing done. The results showed I was actually able to eat some tree nuts. When I called my mom with the good news, she wasn’t shocked. She said I was not actaully tested for anything other than peanuts, but the doctor had told my mom I should avoid tree nuts anyway. This approach was apparently not all that uncommon when I was diagnosed as a toddler.

“That’s something that’s changed a lot,” Backman said. “Ten years ago, if someone was allergic to one tree nut, they’d say avoid all. Now the push is if you’re allergic to pecans, eat other tree nuts.”

Backman said over the past several decades, doctors changed their thinking on allergies and now encourage parents to get these foods into children’s diets sooner, as research shows it could prevent allergies. Merely being exposed to a food (for example my being around tree nuts and never actually eating them) can actually increase the risk of allergies.

So could my allergies to other tree nuts have been prevented had science been better? Maybe. But there’s still hope I can someday eat an Almond Joy without having to whip out my EpiPen.

Backman said not only is there a chance I could grow out of my allergy, but there’s hope a treatment for allergies may be available down the road. Right now, desensitization treatments, where patients eat small amounts of an allergen to build up a tolerance, are still experimental, but are showing promise.

“There’s a lot of hope on the horizon,” he said. “We’re hopeful within the next five to 10 years to have some treatment. The goal is a cure.”

ekayata@hearstmediact.com; @erin_kayata