Sunset Primary School principal Niels Rasmussen said for a lot of families, taking kids to the doctor was too expensive.
"If it's something serious like an emergency and the kiddie needs emergency treatment then it's about getting up to the hospital and getting treatment.
"For some people it's about catching a bus or liaising with an ambulance."
But parents at the decile one school, with a roll of 98, would delay seeking help for non-urgent problems such as sores.
"[They'll] think, 'Oh yeah, that's not bad enough, it'll get better'. It's a bit of wishful thinking," he said.
Illnesses that could be helped with antibiotics at an early stage such as strep throat were often ignored and became more serious, he said.
New Zealand Principals' Federation president Philip Harding said out-of-school factors were "critically important" to a child's education.
"One of [these factors] is their health, and the other one is nutrition and food. To see at least one area ... being tackled by the Budget is a positive sign," he said.
"Schools are a microcosm of breeding bugs and nobody wants to be in a room with sick children."
While most schools had the right to send sick kids home, childcare arrangements were a problem and the child's condition often wasn't followed up on at home.
"So having this access is really important, particularly for parents for whom payment would be an issue."
Children's Commissioner Russell Wills said every winter, preschool and primary-aged children with chest and skin infections that had been left too long crowded the children's wards.
"We commonly find that parents didn't take their child to the GP because they couldn't afford it," he said.
"If they'd been able to, that admission could've been prevented."
He was pleased the policy covered after-hours doctors' visits, which was essential as 40 per cent of children in poverty had working parents. "They tend to take their child after-hours and it's $50-$60 - they simply can't afford it."
Other family oriented spends announced in the Budget included the extension of paid parental leave from 14 weeks to 18 weeks by 2016, and an increase in the parental tax credit from $150 a week to $220 for parents who don't qualify for paid leave. The Government also announced it would put $857 million of new spend into schools and early childhood education over four years.
Get Well Soon
- Doctors' visits free for children up to the age of 13.
- Prescriptions will also be free for all children aged 12 and under.
- Changes kick in from July 1, 2015.
- Policy will cost $90 million over next three years.