Staff did treat him with his medication that was kept in the school's office before the ambulance arrived but it sadly did not work.
Hudson said: "Karanbir Cheema, known as Karan, was a popular Year 8 student. He had many friends who are devastated at his death, as are the staff.
"He was a bright and keen student who excelled in maths. Our thoughts and prayers are with Karan's family."
Karan was taken ill at around 11.30am last Wednesday, June 28, and was rushed to hospital in a life-threatening condition.
Hudson said: "(Karan) was able to come to the school office to indicate that he thought he was having an extreme reaction and they were able to immediately administer the normal treatment, which was kept in the office for his care.
"Very, very tragically in this situation this was not effective."
She added: "Staff at the school reacted promptly to provide medical intervention and were well supported by the London Ambulance Service who attended the scene.
"The school has robust care plans in place for students with identified medical requirements and Karan's care plan was promptly put in place.
"But in light of this tragic incident a review of the procedures will be carried out to ensure that the highest level of standards is maintained.
"The school will not comment on any criminal investigation in relation to this incident."
A neighbour of the Cheemas, who did not wish to be identified, said: "It's awful news, really awful. He was a lovely boy, him and his brother.
"Always polite, friendly, lovely really. They used to play football in the garden all the time.
"He had a little brother and they were always out playing. I didn't know what had happened. The last time I saw him must have been a couple of weeks ago.
"Its such a shame. It really is."
Another neighbour of Cheema said that she had told him ten years ago that her son suffered from a "serious skin complaint".
"I remember her telling me that he had serious skin complaint, that would have been around ten years ago," he said.
A post-mortem examination is due to take place on Wednesday.
William Perkin Church of England High School is rated outstanding by both Ofsted and the Statutory Inspection of Anglican and Methodist Schools (SIAMS, which determines the distinctiveness and effectiveness of a church school.
This article originally appeared on the Daily Telegraph.