Jenny Taylor, an American now living in the UK, wrote about the time she gave her son his very first bite of a peanut butter and jam sandwich while he was weaning, and she wasn't prepared for the reaction he would have.
Her son, known only as 'B', began gagging, coughing and gasping for air.
"Your eyes rolled in the back of your head," Taylor wrote on her blog Let's Talk Mommy.
"I froze and could faintly hear the sound of daddy’s work shoes running into the kitchen towards you. I quickly wiped as much of it out of your mouth as I could as you continued to vomit.
"We knew we needed to get you to the hospital immediately."
Taylor explained that before the family entered the hospital, her son had become unconscious.
"I ripped you out of your car seat and I held you as tight as possible screaming to Daddy to hurry," she continued. "I thought you were dead.
"A doctor to the right of me moved faster than I had ever seen anyone move and gave you a shot that made you gasp and me cry out in relief.
"My baby was alive. He saved my son."
But it wasn't easy for the family. Taylor's son had to be given medicine injections regularly as the peanut butter he had digested kept attacking his system.
He had hives all over his body, in his eyes and mouth.
B was soon moved to a bigger children's hospital and Taylor was told her son had suffered a "deadly allergic reaction" to peanut butter.
But as B started to get better, Taylor said fear took over, as she worried about the ingredients in foods and how she was going to keep him safe.
She was sent home from hospital with her son and his epi pen and said she was paranoid about what to feed him for months.
"At the time, I felt lonely, scared and lost," Taylor told The Huffington Post UK.
"I didn’t know how to go out in public and keep him safe from everyone else. It was definitely a lonely journey in learning how to cope and how to handle his allergies.
"As he got older, more allergies started to appear. It makes you panic a little but you realise your child can still live a happy, healthy, normal life and you hold on to that.
"Now, we know how to take caution when we need to and teach him and as much as ourselves about his allergies. It is our way of life now and we don’t know any different.
"It’s like becoming the best observer in the world to the people around you, your environmental surroundings, and anything you touch as well as your children when you eat."
Taylor wrote the blog in the hope that it will lead more parents weaning their children to become aware of the potential fatal effects of unidentified food allergies.
"I have had to become a pro at reading labels and seeing signs of him struggling if he ate something not right," she wrote.
"I have to pay more attention to him than I do my daughter especially when we are out and about for the day if there is food around.
"I sometimes get angry and wish I would have known more about allergies and dangers of food when I was weaning him. Nuts and eggs included as these are the two we have had issues with the most.
"I didn’t know it but my son had baby eczema badly, and baby asthma, I was told this can be a warning sign they may have food allergies.
"There is nothing scarier than seeing your child go blue, seeing them choke and gasp for air knowing you can’t do anything for them.
"The pain that rips through your body, the tightening in your throat and chest as you hold your breath until they breathe again themselves. It’s something that changes you, stays with you forever.
"If my experience can help but one parent be cautious about food allergies while weaning than it was worth reliving it to share with you."
Taylor explained the best way to manage her son's allergies is to spread the word as far as possible about his allergies: to the school, to the people on the playground, to the doctors that touch him, to friends that come over to play, to his soccer coach, to his swimming instructor.
"Everyone he comes into contact with knows about his allergies," she said.
"It’s frustrating to always be making people aware wherever we go but necessary to give him a better chance to live a long, safe life."