Lucy-Jo Hudson feared she was "losing" her three-year-old son when his mouth went blue and he started to "go all limp".
The 'Hollyoaks' actress - who plays Donna-Marie Quinn in the Channel 4 soap - has told how she was in tears while rushing Carter, three, to hospital, and it was later discovered he has a nut allergy.
Lucy-Jo, 40, wrote on Instagram: "Sooooo this is something I’ve never really shared on here. I’ve read so many stories about other parents and their kids having allergies. My boy Carter has quite a few allergies including milk, and pet hair, but his main one is the worst one you read about which is a nut allergy.
"I've seen posts pop up on my feed recently and thought do you know what? Maybe it’s time I shared our story. Being a mum has its own worries and stresses but being a mum with a son that has a severe nut allergy can really cause a lot of anxiety!
"Carter was 18 months. He was in the trolley, eating snacks while I was getting tea with sienna, and he suddenly looked at me and I knew something was severely wrong!
"He went grey, his mouth went blue and he started to go all limp. He was struggling to catch his breath. God did my heart sink, I literally grabbed him out of the trolley, abandoned the shopping and sienna and I just ran to my car! I strapped him in his car seat (which was awful because at this point he was going in and out of consciousness and his skin was going all mottled, and I couldn’t hold him close as I had to drive to A E! It was 10 minutes but it felt like a lifetime, my poor sienna was crying in the back asking me if he was going to die I kept trying to reassure her he was fine but I couldn’t stop the tears, I honestly thought we were losing him! I kept talking to him, telling him to stay with us and he was trying god love him! I remember pulling up outside A E and I just ran into the hospital cradling carter with sienna by my side and screaming “he’s not breathing” . The nurses flew out of every door and took my baby out of my arms and took him straight into a private room…. After that it all felt like a blur.... Nurse after nurse came in, drs round him, oxygen mask on, adrenalin in his leg, honestly the room was full of nurses trying to bring him round! It was the most terrifying moment of my life!"
Lucy-Jo - who also has nine-year-old daughter Sienna with her ex-husband, 'Coronation Street' star Alan Halsall - has thanked hospital staff for saving Carter's life, admitting she and her partner Lewis Devine are "forever grateful".
She added: "Carters nut allergy is something we have to learn to live with... we read every label, tell every restaurant and we carry his Epi-pens everywhere we go.
"Thankyou to the amazing staff at Ormskirk Hospital for saving our boys life! We will be forever grateful"