It may be Christmas, but it is business as usual at Leicester Royal Infirmary children’s emergency department. Anxious families sit in the waiting room, receptionists deal with the stream of admissions and doctors continue on their never-ending rounds. The only concessions to the festive season are the murmur of a Christmas film on the television and some tinsel in the corridors.

Given the unrelenting pace of life in the NHS, Dr Damian Roland, a consultant in paediatric emergency medicine, says the social background of his patients is not on his mind when they arrive for treatment. But during a brief lull in another frantic day, he reflects on how child poverty is manifesting itself in the young people he treats.

“I don’t have time to sit with families for ages and discuss those particular social issues or have any chance of doing anything about it,” he says. “But clearly it’s important – and it’s affecting children. We need to recognise it as an issue, and there needs to be a debate about the public health responsibilities of frontline NHS services.”

It comes as no surprise to senior doctors such as Roland that deprivation is playing a part in poor children appearing at hospital more often than their richer counterparts. However, an eye-opening study for the Nuffield Trust, revealed in the Observer and based on hundreds of thousands of patient records over a decade, brings new and depressing evidence.

For condition after condition, the poorest fifth of young people are admitted in greater numbers than the richest fifth. In cases of tonsillitis, viral infections, abdominal pain, respiratory infections, convulsions, gastroenteritis, poisoning, chest pain – even head injuries – the poorest young people were admitted for emergency treatment at rates 40% or more higher than the richest.

In the case of some conditions such as epilepsy the gap has been closed, suggesting that education campaigns and a good strategy can help. But no medical professional believes that awareness campaigns designed to head off emergencies will on their own stop poor children needlessly turning up at hospital.

The worry is that with the NHS under pressure, a housing crisis and state spending squeezed, things will get worse before they get better – while stagnant wages are heaping pressure on families less able to cope with a medical issue that is allowed to become an emergency.

One of the report’s authors, Dr Ronny Cheung, a paediatric consultant at the Evelina children’s hospital, London, says he is seeing a growing evidence of conditions not only exacerbated by poverty, but caused by it. “I’m seeing kids with rickets on a fairly regular basis in my clinic,” he says. “That is related to nutrition at the very least. We are seeing more advanced cases. It should be a Victorian illness. It shouldn’t be around to this degree any more.

“What we see on a weekly basis is that poorer families who come in often take their children into hospital a bit later than they otherwise would. Maybe that’s partly down to health literacy, but – and I’ve spoke to parents about this – it is a struggle for them to bring children in. If your ability to make a living is on the line, your threshold for taking time off work to check a child’s health is going to be higher.”

Rates of admission for asthma are particularly alarming, having risen over the last decade – the poorest young people are now well over twice as likely to be admitted for the condition as the rich. Medical experts say that environment, and above all poor housing, is a prime cause.

According to the latest government data, there were 121,360 children in temporary accommodation in England in the third quarter of 2017 – with more than 88,000 of those in London. It is the highest number in a decade. The figure in London represents a 52% growth over the last five years. In the capital alone, more than 3,000 children are living in bed and breakfasts, or hostels.

“Housing problems can have a major impact on child health – whether that’s increased likelihood of respiratory problems because of poor housing conditions, or mental ill-health,” said Dr Dougal Hargreaves, of the UCL Institute of Child Health. “In a recent survey of paediatricians, over 40% had difficulty discharging a child in the last six months because of concerns about housing or food insecurity.”

The Nuffield study is published as years of progress in cutting child poverty is being reversed. Research by the Joseph Rowntree Foundation earlier this month found almost 400,000 more children in the UK were living in poverty last year compared with 2012-13. It warned that decades of progress were being erased due to stagnant wages and inflation. It has called on the government to unfreeze working-age benefits and build decent, affordable homes.

Meanwhile, the Institute for Fiscal Studies estimates the number of children living in poverty is likely to rise to a record 5.2 million over the next five years. The Nuffield report suggests that this also has serious consequences for an NHS already under strain.

The pressures of that poverty on families, Dr Cheung says, are becoming tragically clear. “A few months ago we had discussions with social services about whether a child was being cared for properly,” he recalls. “But it just turned out that the mother was working two jobs, she had two other children and was simply under pressure not to take more time off to go to an asthma appointment. In the end, we agreed to see the child at home because that was the only way we could make it work.

“This is about life chances. It’s about the fact that a quarter of the children in this country live in material poverty. It’s about a lack of social mobility. It’s a cycle.”