A young boy nearly killed by a dose of ibuprofen have been dealt a second devastating blow - after doctors told him he is going blind. Calvin Lock came down with a suspected viral infection in 2012 and was given a single dose of strawberry-flavoured liquid Nurofen by his mother. But the painkiller triggered an extremely rare reaction which caused his body to burst into blisters and his hair and fingernails to fall out. The now 13-year-old lost 65 per cent of his skin and had to be put on a life support machine for three days. Scroll down for video . Calvin Lock, 13,  has been dealt a devastating blow as doctors say he will go blind due to Severe Ocular Surface Disease, which affects the corneas. In 2012 he suffered a horrific reaction to a dose of Ibuprofen, causing his skin to blister and fall off (right) Calvin Lock, 13, (pictured with mother Robyn Moult and stepfather Daryn Chamber) has been dealt a devastating blow as doctors say he will go blind due to Severe Ocular Surface Disease, which affects the corneas. In 2012 he suffered a horrific reaction to a dose of ibuprofen, causing his skin to blister and fall off . His mother has released pictures of Calvin to raise awareness of Steven Johnson Syndrome, the rare reaction he suffered. Doctors initially diagnosed the then 11-year-old with chicken pox, left, after a rash appeared. But they soon discovered it was SJS which causes skin cells to die and shed, right . Another side-effect of SJS is developing Severe Ocular Surface disease, caused by excessive scarring from the reaction to Ibuprofen. He also suffers trichiasis, where the eyelashes grow inwards . Doctors initially told his family he only had chicken pox, before diagnosing Stevens Johnson syndrome (SJS), which causes the skin cells die and large parts to shed like a snake. But Calvin's condition worsened and he developed the more serious form of the condition, Toxic Epidermal Necrolysis, meaning his skin was burning from the inside out. He spent nearly three weeks in Addenbrooke's Hospital receiving treatment before being allowed back to his home in Littleport, Cambridgeshire. His mother Robyn Moult, 40, and stepfather Daryn Chambers, 49, were amazed he survived the condition, which affects around one or two people per million a year. But they have now been left devastated after Calvin developed a painful eye disease that will leave him blind in both eyes within the next two years. He has been diagnosed with Severe Ocular Surface disease  - a severe condition affecting the corneas of his eyes. Stevens Johnson syndrome (SJS) is a severe adverse reaction to a medication. It was named after two US paediatricians who first described it in 1922. It affects around one to two people per million and is more common among women. Symptoms include skin rashes, blisters in the mouth, ears and nose and swelling of the eyelids. If left untreated the condition can result in death. Possible complications include permanent blindness and lung damage. Once diagnosed doctors will immediately stop the patient taking the offending drug. Treatment includes IV fluids and high calorie formulas to promote healing. Antibiotics are given when necessary to prevent secondary infections such as sepsis. Pain medications such as morphine can make the patient more comfortable. The excessive scarring from the reaction to ibuprofen caused cornea erosions, and scarring of the eye's mucous membranes which affect his eyelids. He also has trichiasis, where the eyelashes grow inwards and has growing vitreous adhesions which causes the gel that fills up the inside of the eye to shrink, liquify and stick to the retina - resulting in blindness. He has had to have operations to attempt to fix his sight, electrolysis to rid his eyes of his eyelashes and further surgery to stop his eyelids from turning inwards. The teenager already struggles to see the board at school, can no longer play video games. And he has to have eye drops put in every hour of every day. Calvin also suffers chronic fatigue, full body scarring, mouth and throat problems, depression, and has been diagnosed with post traumatic stress disorder (PTSD). Mrs Moult, who has three older children, said: 'It's an autoimmune condition which will never go away. 'His body will constantly attack itself forever and it's devastating to watch. 'Calvy feels like he has constant grit in his eye, it's extremely painful for him. I try to make him take responsibility but I also don't want to nag, I feel helpless. 'If he forgets to put his eye drops in he's left rolling on the floor in agony. The condition left him with memory loss and this means he frequently does forget. 'He struggles to run around with his friends, it's so much to recover from and he keeps trying to fight it and can't accept that his life has changed. 'His personality is different now, what he went through was so traumatic that he needs treatment for PTSD. Calvin will be talking about his experience next year at the House of Commons where we will be campaigning for National SJS Awareness and launching the first NHS Awareness Poster Campaign . 'He's so intelligent and bright but now he can't be bothered with school, he doesn't see the point because he doesn't think he has a future without his eyesight.' The couple are now planning legal action against the NHS, claiming the original misdiagnosis has made his condition much worse. They claim Addenbrooke's could have done more to prevent the infection and its side effects if staff had acted sooner. The couple say he was twice wrongly diagnosed with chickenpox and a specialist witness employed by their legal team said the diagnosis should have been put to a more senior doctor. They also believe he would have recovered quicker if he had been transferred straight away to the burns unit in Essex. Mrs Moult said: 'There should have been a thorough investigation. 'Clearly the doctor should have consulted a senior member of staff about Calvin's diagnosis. 'He definitely should have been transferred straight to the burns department to prevent more trauma and scarring. 'His care was inadequate and it's left him with debilitating conditions. 'I'm determined he will have a career and an education, and we want to be able to buy him the equipment he will need, such as audio technology, to help him through life.' Calvin fell ill on September 19, 2012 with a sore throat and Mrs Moult gave him the liquid Nurofen after his GP said he had a viral infection. Six days later he returned to the GP with a rash and was diagnosed with chickenpox - which SJS is often mistaken for - and given antibiotics. Calvin, pictured before he suffered the rare reaction to the painkiller in 2011 . The next morning, swelling and rashes had appeared across his body and he was taken to Addenbrooke's Hospital. Doctors there also diagnosed chickenpox but it took 24 hours to admit him as an in-patient by which time he was struggling to breathe and unable to walk, talk or see. Calvin was put on a drip as staff started treated more than 200 painful blisters but his condition deteriorated and he was put on a life-support machine. He was transferred to a burns unit where surgeons removed affected skin from 65 per cent of his body. He has now been diagnosed with a range of eye problems which doctors warn will leave him blind, and has already endured operations to fix his sight. Calvin will be talking about his experience next year at The House of Commons where we will be campaigning for National SJS Awareness and launching the first NHS Awareness Poster Campaign. He and his mother have just had their charity SJS Awareness officially registered and started a website sjsawareness.org.uk . A spokesman for Nurofen for Children told the Mail at the time, warnings about the reactions suffered by Calvin are included on the patient information leaflet in 'consumer friendly language'. A spokesperson for Cambridge University Hospitals, who run Addenbrooke's Hospital, said: 'We are unable to comment on individual cases as this would breach patient confidentiality.'
Calvin Lock, 11, was given the painkiller to tackle a viral infection .
Suffered a rare but severe reaction that caused his  skin to burn off .
Reaction was originally mistaken for chickenpox, delaying treatment .
Has  been told a serious eye condition will leave him blind within 2 years .
Parents are launching action against the NHS for initial misdiagnosis .
A young boy nearly killed by a dose of ibuprofen have been dealt a second devastating blow - after doctors told him he is going blind. Calvin Lock came down with a suspected viral infection in 2012 and was given a single dose of strawberry-flavoured liquid Nurofen by his mother. But the painkiller triggered an extremely rare reaction which caused his body to burst into blisters and his hair and fingernails to fall out. The now 13-year-old lost 65 per cent of his skin and had to be put on a life support machine for three days. Scroll down for video . Calvin Lock, 13,  has been dealt a devastating blow as doctors say he will go blind due to Severe Ocular Surface Disease, which affects the corneas. In 2012 he suffered a horrific reaction to a dose of Ibuprofen, causing his skin to blister and fall off (right) Calvin Lock, 13, (pictured with mother Robyn Moult and stepfather Daryn Chamber) has been dealt a devastating blow as doctors say he will go blind due to Severe Ocular Surface Disease, which affects the corneas. In 2012 he suffered a horrific reaction to a dose of ibuprofen, causing his skin to blister and fall off . His mother has released pictures of Calvin to raise awareness of Steven Johnson Syndrome, the rare reaction he suffered. Doctors initially diagnosed the then 11-year-old with chicken pox, left, after a rash appeared. But they soon discovered it was SJS which causes skin cells to die and shed, right . Another side-effect of SJS is developing Severe Ocular Surface disease, caused by excessive scarring from the reaction to Ibuprofen. He also suffers trichiasis, where the eyelashes grow inwards . Doctors initially told his family he only had chicken pox, before diagnosing Stevens Johnson syndrome (SJS), which causes the skin cells die and large parts to shed like a snake. But Calvin's condition worsened and he developed the more serious form of the condition, Toxic Epidermal Necrolysis, meaning his skin was burning from the inside out. He spent nearly three weeks in Addenbrooke's Hospital receiving treatment before being allowed back to his home in Littleport, Cambridgeshire. His mother Robyn Moult, 40, and stepfather Daryn Chambers, 49, were amazed he survived the condition, which affects around one or two people per million a year. But they have now been left devastated after Calvin developed a painful eye disease that will leave him blind in both eyes within the next two years. He has been diagnosed with Severe Ocular Surface disease  - a severe condition affecting the corneas of his eyes. Stevens Johnson syndrome (SJS) is a severe adverse reaction to a medication. It was named after two US paediatricians who first described it in 1922. It affects around one to two people per million and is more common among women. Symptoms include skin rashes, blisters in the mouth, ears and nose and swelling of the eyelids. If left untreated the condition can result in death. Possible complications include permanent blindness and lung damage. Once diagnosed doctors will immediately stop the patient taking the offending drug. Treatment includes IV fluids and high calorie formulas to promote healing. Antibiotics are given when necessary to prevent secondary infections such as sepsis. Pain medications such as morphine can make the patient more comfortable. The excessive scarring from the reaction to ibuprofen caused cornea erosions, and scarring of the eye's mucous membranes which affect his eyelids. He also has trichiasis, where the eyelashes grow inwards and has growing vitreous adhesions which causes the gel that fills up the inside of the eye to shrink, liquify and stick to the retina - resulting in blindness. He has had to have operations to attempt to fix his sight, electrolysis to rid his eyes of his eyelashes and further surgery to stop his eyelids from turning inwards. The teenager already struggles to see the board at school, can no longer play video games. And he has to have eye drops put in every hour of every day. Calvin also suffers chronic fatigue, full body scarring, mouth and throat problems, depression, and has been diagnosed with post traumatic stress disorder (PTSD). Mrs Moult, who has three older children, said: 'It's an autoimmune condition which will never go away. 'His body will constantly attack itself forever and it's devastating to watch. 'Calvy feels like he has constant grit in his eye, it's extremely painful for him. I try to make him take responsibility but I also don't want to nag, I feel helpless. 'If he forgets to put his eye drops in he's left rolling on the floor in agony. The condition left him with memory loss and this means he frequently does forget. 'He struggles to run around with his friends, it's so much to recover from and he keeps trying to fight it and can't accept that his life has changed. 'His personality is different now, what he went through was so traumatic that he needs treatment for PTSD. Calvin will be talking about his experience next year at the House of Commons where we will be campaigning for National SJS Awareness and launching the first NHS Awareness Poster Campaign . 'He's so intelligent and bright but now he can't be bothered with school, he doesn't see the point because he doesn't think he has a future without his eyesight.' The couple are now planning legal action against the NHS, claiming the original misdiagnosis has made his condition much worse. They claim Addenbrooke's could have done more to prevent the infection and its side effects if staff had acted sooner. The couple say he was twice wrongly diagnosed with chickenpox and a specialist witness employed by their legal team said the diagnosis should have been put to a more senior doctor. They also believe he would have recovered quicker if he had been transferred straight away to the burns unit in Essex. Mrs Moult said: 'There should have been a thorough investigation. 'Clearly the doctor should have consulted a senior member of staff about Calvin's diagnosis. 'He definitely should have been transferred straight to the burns department to prevent more trauma and scarring. 'His care was inadequate and it's left him with debilitating conditions. 'I'm determined he will have a career and an education, and we want to be able to buy him the equipment he will need, such as audio technology, to help him through life.' Calvin fell ill on September 19, 2012 with a sore throat and Mrs Moult gave him the liquid Nurofen after his GP said he had a viral infection. Six days later he returned to the GP with a rash and was diagnosed with chickenpox - which SJS is often mistaken for - and given antibiotics. Calvin, pictured before he suffered the rare reaction to the painkiller in 2011 . The next morning, swelling and rashes had appeared across his body and he was taken to Addenbrooke's Hospital. Doctors there also diagnosed chickenpox but it took 24 hours to admit him as an in-patient by which time he was struggling to breathe and unable to walk, talk or see. Calvin was put on a drip as staff started treated more than 200 painful blisters but his condition deteriorated and he was put on a life-support machine. He was transferred to a burns unit where surgeons removed affected skin from 65 per cent of his body. He has now been diagnosed with a range of eye problems which doctors warn will leave him blind, and has already endured operations to fix his sight. Calvin will be talking about his experience next year at The House of Commons where we will be campaigning for National SJS Awareness and launching the first NHS Awareness Poster Campaign. He and his mother have just had their charity SJS Awareness officially registered and started a website sjsawareness.org.uk . A spokesman for Nurofen for Children told the Mail at the time, warnings about the reactions suffered by Calvin are included on the patient information leaflet in 'consumer friendly language'. A spokesperson for Cambridge University Hospitals, who run Addenbrooke's Hospital, said: 'We are unable to comment on individual cases as this would breach patient confidentiality.'
rare reaction which caused his body to burst into Ibuprofen, causing his skin to blister and fall off (right) Calvin Lock, 13, (pictured with disease that will leave him blind in both eyes within the next two years. He has been diagnosed planning legal action against the NHS, claiming the original misdiagnosis has made his condition he was twice wrongly diagnosed with chickenpox his GP said he had a viral infection. Six days mistaken for - and given antibiotics. Calvin,