A senior paramedic who treated a schoolboy with a dairy allergy who collapsed after cheese was "flicked" on him mistakenly believed it to be a severe asthma attack and also gave him a substance not meant for children, an inquest has heard.
Asthmatic Karanbir Cheema, 13, who also had allergies to wheat, gluten, egg, milk and tree nuts, suffered from a severe reaction at his school in west London on June 28 2017.
He was taken to hospital in a life-threatening condition but died almost two weeks later with his parents by his side at Great Ormond Street Hospital on July 9.
Alexandra Ulrich, of the London Ambulance Service (LAS), told Karanbir's inquest his symptoms appeared to be more consistent with a severe asthma attack and she could see no rash, hives or swelling.
She told St Pancras Coroner's court on Friday she administered two grams of magnesium sulfate - used to treat muscle spasms during life-threatening asthma attacks.
The paramedic of more than 10 years experience said: "If I had known about the specific details of the history about the allergens, I wouldn't have given it."
Ms Ulrich said it is not routinely given for anaphylaxis and she would have called a doctor to discuss the case if she had known of the teenager's multiple allergies.
A pocketbook issued to ambulance staff has now been updated to make explicit the substance is not meant for under-18s, she added.
She told the hearing: "When we arrive, people look to us for answers and to fix things.
"A child has deteriorated quickly and we have a short window of opportunity to try and reverse that. I think I was in the mindset we only had seconds or minutes.
"I think I was probably keen to deliver that care and maximise that window of opportunity."
Ms Ulrich only became aware of Karanbir's allergy history when arriving at hospital with the teenager, whose mother Rina had also travelled in the ambulance, the hearing was told.
Coroner Mary Hassell said: "It just sounds like you were missing that few seconds to step back and say 'What do we have here?'
"Would you manage the situation any differently tomorrow?"
Ms Ulrich replied: "I think I would try to get more information, I'd try to understand the detail of what had happened."
The teenager who threw the cheese on Karanbir told the inquest he was only "playing around" and did not mean harm.
He said he did not realise allergies were serious and thought someone would simply suffer a rash or fever.
The boy, who cannot be named for legal reasons, told the hearing he thought Karanbir was allergic only to bread.
The incident happened at Perkin Church of England high school in Greenford, west London.
The inquest continues.