The devastated mother of a severely allergic teenager who died after a classmate flicked a slice of cheese at his neck has shared a heartbreaking final image of her son lying in hospital.

Karanbir Cheema, known as Karan, was 13 when he died in July 2017, ten days after he fell unconscious when cheese was thrown at him during break time at William Perkin Church of England High School in Greenford, West London.

His mother, Rina Cheema, 53, made the decision to turn off his life support machine. In that time his body had deteriorated, going into cardiac arrest and suffering from brain damage and lack of oxygen to the brain.

She has now revealed that since the tragedy, she has been 'living in a black hole' and that her son's death is 'something that's going to haunt me for the rest of my life'.

In a tragic image from his hospital bed, soon before he passed, the youngster can be seen with tubes in his mouth and linked up to a life-support machine. Ms Cheema shared it as she wants people to understand an allergy can kill

Ms Cheema has called for there to be more education in school and that more needs to be done to educate children on allergies (Karan and Rina pictured)

Speaking to the BBC, she said: 'I sent him to a place where I thought he'd be safe only to find out nobody knew what they were doing. If they knew that allergies cause problems - it's no problem giving an EpiPen.

'They could have given him an EpiPen. Or even dialled 999 straight away. He would be here with me today.'

In a tragic image from his hospital bed, soon before he passed, the youngster can be seen with tubes in his mouth and linked up to a life-support machine. Ms Cheema shared it as she wants people to understand an allergy can kill.

The cheese thrown at Karan, no bigger than half the size of a Post-It note, caused an 'extraordinary reaction' after coming into contact with his skin, one which an expert at the inquest described as 'unprecedented' in medical circles.

Karanbir Cheema, known as Karan, was 13 when he died in July 2017, 10 days after he fell unconscious after the cheese was flicked at his neck while on a break at his school in Greenford, West London

It comes as it was also revealed the incident is now being investigated by the Health and Safety Executive, and as Ms Cheema campaigns for schools to educate pupils and staff about the risks of allergies and how to deal with them.

At an inquest held into the youngster's death earlier this year, Senior coroner Mary Hassell recorded a narrative conclusion and said the main factor was his severe allergy. She added the pupil who flicked the cheese did not mean any harm and 'all of the evidence point to the cheese being responsible for Karanbir's death.'

However, Ms Hassell said Karan's school did not properly educate pupils about the 'grave consequences' of his allergies, and that the school's healthcare provision was inadequate.

Speaking about the pain of turning off her son's life support machine, Miss Cheema told Holly and Phil on This Morning: 'We didn't want to switch it off – it wasn't fair on his little body to go through this.

'He smiled when the machine was turned off, they took him into another room and we said our last good byes before he was taken down and he had a smile on his face.'

She added: 'You're always praying for the last minute miracle his brothers and sisters and his uncles were all there beside him.'

Karan suffered allergies to dairy, wheat, gluten, eggs and nuts and suffered from asthma and eczema. Rina took painstaking care over her son's diet, using a separate grill, microwave and fridge for him. On their last morning together, she gave him specially prepared flapjacks and oat milk.

As well as making sure she always carried an EpiPen, she gave one to the school, along with antihistamine medicine, a spare asthma pump and hydrocortisone cream, to be kept in a personal medical box in the school office.

Speaking about the pain of turning off her son's life support machine, Miss Cheema said he smiled as it happened

Karan (pictured in a family photo) was also severely allergic to wheat, gluten, eggs and nuts and suffered from asthma and atopic eczema

William Perkin Church of England High School in Greenford, West London, did not properly educate pupils about the 'grave consequences' of his allergies, according to Senior coroner Mary Hassell

The events of that tragic day — June 28, 2017 — are etched in Rina's mind, starting with an incident of childish stupidity, when a pupil eating a baguette gave a piece of cheese to another boy.

The boy, who had previously been reprimanded for throwing food at other pupils, then flicked the cheese at Karan. He said in court that he knew he was allergic to bread, but didn't know about his dairy allergy. 'I think it landed on the left side of his neck,' he said. 'Karan told me: 'I'm allergic to cheese.' I apologised after that.'

The student responsible was arrested on suspicion of attempted murder and interviewed by police but never faced charges and was later expelled from school.

He said he didn't know that Karan's allergies were 'that serious' and thought he would 'get a rash or have a fever or something similar to that' when he flicked the cheese at him.

A statement released by Twyford C of E Academies Trust earlier said Karan's death has 'highlighted the significant challenges for school in managing students with the most severe medical needs.'

The school, which said it now holds two spare EpiPens, said there was 'a lack of clarity and consistency in guidance provided to schools'.