Anne Longfield said that school nurses are increasingly becoming less accessible to children and young people, as a result of their heavy caseloads. Many are spending twice as much time on paperwork than on direct work with children.
In a new report, based on responses from 775 school nurses, the commissioner said nurses also do not get enough time to spend on proactive work, such as health education.
Thirteen per cent of nurses surveyed said they spent most of their day filling in paperwork. The report found that some nurses were responsible for the health and wellbeing of thousands of children, with two-thirds of nurses looking after more than five schools each.
When it came to child protection, 23 per cent of 409 nurses said they had difficulty contacting social workers and social services when they had concerns about children.
Of 382 nurses, 41 per cent said they were also unhappy with the outcome of at least half of the referrals they made to social services.
Professionals at the front line
The report found that school nurses are increasingly picking up work traditionally done by social workers, with a fifth saying they felt that their child protection caseload was limiting their capacity to do other things, including face-to-face work.
Workforce figures show that, in May 2010, there were 2,987 full-time equivalent school nurses in England. By May 2016, this had dropped to 2,630.
Ms Longfield said: "School nurses have a vital role to play in schools protecting children as well as promoting their wellbeing.
"They are one of the professionals at the front line, identifying abuse or neglect, as well as supporting children with a host of other issues – whether that's mental health, age-appropriate relationships and sex education or healthy eating. Being available for children for face-to-face time is irreplaceable.
"It is clear from this research that school nurses face significant barriers in working directly with children and young people, with paperwork getting in the way. The support they offer needs to be better promoted and new ways to enhance their engagement with children explored."
'Bearing the brunt'
Fiona Smith, the Royal College of Nursing's professional lead for children and young people's nursing, said: "This report echoes what many RCN members have been telling us for some time – school nurses do not have the time or resources to carry out their roles as effectively as they would like to.
"A major part of the problem is that the number of school nurses is dropping all the time – despite the vital importance of what they do. Children and young people are bearing the brunt of these public-sector funding cuts, with potentially serious consequences for the future."