AJ Buckalew took two bites of his pepperoni pizza and immediately knew something was wrong. He touched his mom’s arm to get her attention.

“Mom, something’s not right,” he said. Irene Buckalew glanced down at his plate in the restaurant.

“Oh my God, it’s regular cheese,” she said. She injected his leg with an EpiPen to try to stop the life-threatening allergic reaction her son has to dairy.

It didn’t take.

The Chesterfield, Missouri, family has been in this situation before, but never at Mellow Mushroom, a pizzeria chain they first tried on vacation after reading positive reviews about it on allergy-friendly restaurant guide Allergy Eats. That was the first time in his life he’d tried pizza at a restaurant. In fact, they’d celebrated AJ’s 13th birthday there a few weeks before, and this was their third visit in two weeks.

“We rarely eat out,” Irene said. “I make everything from scratch all the time.” It’s too risky, given how severe her son’s food allergies are.

Those first pizza outings had gone well.

“I thought it was pretty good,” AJ said of his first slices.

This time was different. AJ got scared when the first shot from the EpiPen didn’t help. He felt his chest tighten. It was getting harder to breathe. He felt flushed. Some hives appeared. He asked his father to call 911, and an ambulance came to take him to the hospital.

The chef told Irene that he had made the pizza with vegan cheese himself. She and AJ left on the ambulance.

“We let our guard down a little bit,” said Irene, who disputes the restaurant’s account.

“We take allergy issues very seriously,” said Chris Deatherage, general manager at the restaurant. They offer gluten-free and vegan pizzas, clean the pizza cutters and use gloves when making them, he said. He spoke to the manager working that night, and says all the proper protocol they have was followed. “We’ve never had an issue like this before,” he said.

Meanwhile, AJ received three more EpiPen injections at the hospital and eventually needed an intravenous epinephrine drip to stop the allergic reaction.

Even when the teen, the parents and the restaurant try to be vigilant and careful, life-threatening mistakes can happen for those navigating the world with severe food allergies. Between 2007 and 2016, treatment of severe food allergy reactions increased by nearly 400 percent, according to data from Food Allergy Research and Education (FARE), a nonprofit that advocates for a more inclusive world for those living with food allergies.

While many people think it’s toddlers and young children who are most at risk when it comes to food allergies, that’s not actually the case, according to Gina Clowes, FARE’s national director of training and outreach. Research shows that teenagers and young adults with food allergies are at the highest risk of fatal food-induced anaphylaxis, she said.

Adolescence is a time of wanting to fit in with peers, and some degree of breaking away from parental rules and testing boundaries. Clowes, who is also raising a teenager with a severe food allergy, says she has learned to prioritize the most important rules, such as never leaving the house without an EpiPen and making sure any friend’s parent has her contact information.

Mistakes can easily happen. There might be recalls on food products, human error or things a teenager might not even think about, such as kissing someone who has eaten something to which they are severely allergic or sharing a vaping product that could trigger an attack.

Irene knows firsthand the stakes attached to the smallest mistakes. When AJ was 10 years old, he ate half of a cupcake that he thought was safe. It turned out to have dairy and egg in it. His mom rushed him to a hospital, where they pumped his stomach, gave him medicines and eventually had to put him on a ventilator for seven or eight hours. He spent two days in the pediatric intensive care unit to recover.

But the newly minted teen rarely complains and says he doesn’t think about his allergies much.

“I try to keep it as not such a big deal,” AJ said. He brings his own food when he goes to sleepovers and parties. He’s learned to trust his own body. Certain parts of childhood that many of us take for granted -- going for ice cream with friends, trick-or-treating on Halloween -- have never been part of his life.

“We’re trying to have him live in this normal world,” his mom said.

But it’s doubtful he’ll try pizza again anytime soon.

A few days ago, I dragged two large plastic tubs from the closet and dumped hundreds of photos on the bedroom floor.

These were old-school photos, processed from film, taken with a camera that you couldn’t use to Google or text. We had documented both of my kids’ earliest years with these archaic devices. I didn’t get a smartphone until my youngest was 5 1/2. Now he’s 13. His older sister recently got her learner’s permit.

We have officially transitioned into the parents of teenagers.

My phone has nearly 16,000 photos on it, having captured most of their moments since those early years. But that’s a digital task for another day. This time, I felt the urge to finally organize the contents of those two boxes. As I sifted through their newborn and toddler years, I heard the words a colleague had offered when they were babies.

“Little kids, little problems; big kids, big problems,” he had said. He was closer to my parents’ age and had already run these gauntlets. Intellectually, I believed him. But in my heart, I kind of doubted it. I was trying to keep these two completely dependent human beings alive! What could be more stressful and demanding than that?

They say you don’t know what you don’t know, and they would be right.

I had no clue what my future worries would be because many of them hadn’t been invented yet! I had never tweeted or posted on Facebook or seen a YouTube video. Any concerns about “screen time” were just about a television screen.

Quaint, isn’t it?

I had worried about their eating and sleep habits back then, and I still worry about those. We kept an eye out for each developmental milestone and tried to protect them from physical dangers.

But now, I also worry about the things you can’t easily measure or see -- their emotional health, their inner lives. When they enter these vulnerable teenage years, you worry about their exposure to drugs and alcohol, cyberbullying, anxiety, depression, social media mistakes and digital addictions. You also feel like you have far less control over the problems your children will encounter. In some ways, they seem like toddlers again in much larger bodies -- risk-taking, defiant, moody and emotional. It makes sense. These are both times of rapid development and growth.

I wish I had been better prepared to understand what was driving my child’s changes in behavior and personality before we entered these turbulent years. Specifically, I wish I had read “The Teenage Brain: A Neuroscientist’s Survival Guide to Raising Adolescents and Young Adults” when my daughter was 10 instead of when she was 15. It would have saved me some grief in years 11, 12 and 13. The book, by neurologist Dr. Frances E. Jensen and journalist Amy Ellis Nutt, helps explains why teenagers can seem so smart and so irrational at the same time.

The most startling part of becoming the parent of teenagers was my own confusion about whether their behavior was “normal,” and figuring out how to effectively respond to it -- how to protect them during these perilous years while still teaching them independence and resiliency. Teenagers are funny and insightful, and have moments when they can be incredibly sweet. They are just as often frustrating and immature, and have moments when they can be incredibly thoughtless.

You can’t help but wonder at times: Shouldn’t they know better by now? Why do I have to keep repeating myself?

That’s why books and articles about teen brain development are so reassuring and helpful. They explain, through biochemistry and biology, much of teens’ seemingly inexplicable behavior. And the science reinforces that parents should err on the side of caution when they sense problems. Teens are so susceptible to risks and dangers, and it’s best to intervene or reach out for help when they might be struggling. It’s impossible to shield adolescents from the mistakes they will inevitably make and traumas they will endure, but you can try to teach them coping skills to blunt the impact.

The physical demands of raising toddlers are relentless, and the mental demands of teens will test one’s sanity and patience. Now, I worry about having enough time to teach them everything we want them to know before they leave for college. Time moves so much faster.

It was reassuring to sit with their old pictures, the physical reminders of fleeting childhood, all around me. I separated their photos into piles and labeled the backs of envelopes. I discovered an empty baby book and album from when my son had been born. Filling those pages didn’t seem possible back in those sleep-deprived, exhausting days when I was caring for a newborn and a 2-year-old. A daily shower seemed ambitious enough then.

A week before he turned 13, I put together the story of my son’s first year. Granted, it was easier because he had far fewer photos than the first child. It was a chance to remind myself that we survived the “little problems” of his little years, and that we’ll weather the “big problems” yet to come.

Right before his teenage years, I finished my son’s baby book.

Just in time for the next chapter.

To teens who Juul:

Hey, guys. We thought this was an area where you all had us beat, hands-down.

For years, cigarette smoking has been falling among high-school students. In fact, it’s fallen to nearly half of what it was when most of your parents were in high school. Thank goodness your generation realized what a nasty and unhealthy habit it is.

But you all have latched onto e-cigarettes -- vaping or Juuling -- because you think it’s safer than the old cancer sticks.

E-cigarette use grew 900 percent among high school students from 2011 to 2015, according to a recent report by the U.S. Surgeon General. In 2015, more than a quarter of students in grades 6 through 12 said they had tried e-cigarettes, along with more than a third of young adults.

Adults didn’t really see this coming, but now we’re all talking about it.

We know that’s not a new USB flash drive. It looks like one, and it even plugs into a laptop to charge, but that device is a way to get a nicotine fix. You carry those pocket-size vaporizers and swap out flavored cartridges that deliver a nicotine hit without tobacco. We’ve heard about the kids who sit in the back of the class sneaking puffs while an unsuspecting teacher lectures. There are middle- and high-school bathrooms filled with vapor between classes. It seems like everyone is doing it, right?

After all, it’s so easy to get. You can lie about your age and buy it online, or go on Snapchat or Instagram and find someone who will sell it to you. We know there’s a local teenager running around like a celebrity, hawking cartridges. But think about this for a minute: Who is trying to convince you that this new kind of smoking is safer? Could it be the same people who will profit from creating a new generation of nicotine addicts? Why do they sell flavors like “gummy bear” and “cotton candy”? Who do you think they are targeting?

The younger you get hooked on nicotine, the longer you’ll be a paying customer. Some research shows that many teens believe they are smoking a “nicotine-free” product. The industry makes its flavored juices in a range of nicotine concentrations, but you have no way of verifying how much you may be getting. And nicotine isn’t the only danger.

There isn’t a huge body of research on the health impacts of vaping on teens, because it’s a relatively new product, having landed in U.S. markets in 2007. But we’re starting to see research emerging. Guess what? These e-cigs are far from harmless.

The vapors you inhale can affect your immune system, some studies show. Teenage vapers are starting to develop “smoker’s cough,” chronic bronchitis and bloody sores in their mouths and throats that are slow to heal.

More data suggests that e-cig vapors may also contain cancer-causing chemicals. There are hundreds of unregulated brands, and thousands of flavors. A cartridge of “juice,” the liquid that goes inside the device, can contain toxic metals, along with the nicotine, propylene glycol, solvents and flavors. Dripping or super-heating the juice can transform chemicals into toxic, carcinogenic ones.

Dr. Nadeem Ahmed, a pulmonary and critical care specialist at St. Anthony’s Health Center in Alton, Illinois, talks to his patients every day about e-cigs. He shared information about recent studies that looked at the lungs of smokers, e-cig users and nonsmokers, and found that e-cig users have a lot more inflammation and inflammatory proteins than nonsmokers.

The vapor itself, even without tobacco, causes inflammation.

Teens who vape are six times more likely to try cigarette smoking than those who have never vaped, research suggests. And Dr. Ahmed said that people don’t generally just abuse one substance.

It’s really hard to quit nicotine. We’ve seen our parents, our friends, our partners struggle to give it up. If you can’t make it through a school day without Juuling, your body is already addicted to a chemical. When you get addicted to nicotine, you can suffer withdrawal symptoms when you try to quit. That means you’re buying more and smoking more.

The teenage brain is primed to get hooked on chemicals more quickly than the adult brain.

A little more than a decade ago, e-cigs looked like the way smokers would be able to kick a habit proven to be hazardous to their health. We didn’t think it would become a way to threaten the progress we’ve made on teenage smoking.

We’ve been so worried about keeping you away from opioids or painkillers or illegal drugs that we didn’t think you would stumble into this nasty habit the way that you have. It’s not a good look.

It looks like you’re gambling with your health and getting played so someone can make a buck off of you.