If your child brings home an uneaten packed lunch it could be a sign of coronavirus, scientists have warned.
More than a third of school-aged children with the disease suffer from a loss of appetite that prompts them to skip meals.
Parents and teachers are now being warned to look out for lesser-known symptoms of the disease as schools go back and the risk of infection goes up.
A team from King's College London have been monitoring hundreds of infected children using a Covid-19 symptom tracker mobile app.
They found the majority of youngsters who test positive do not show classic signs of the virus, such as a persistent cough, fever or loss of smell.
They instead found most youngsters with the virus tended to skip meals, suffer headaches and feel exhausted.
The app also found one in six under-18s break out in skin rashes that are usually very itchy.
The NHS currently only advises people get a test if they have a fever, a continuous cough and a loss of smell or taste.
A third of children with coronavirus skip meals due to a loss of appetite, researchers from King's College London say (file)
The top five symptoms in under-18s with the virus were fatigue (55 per cent) headaches (53 per cent), fever (49 per cent), sore throat (38 per cent) and loss of appetite (35 per cent). This was different compared to the app’s data on adults; fatigue (87 per cent), headache (72 per cent), loss of smell (60 per cent), persistent cough (54 per cent) and sore throats (49 per cent)
More and more Covid-19 symptoms are being reported as doctors and scientists learn more about the virus which emerged from obscurity just months ago.
KCL researchers have identified at least 20, which range from from mild sore throats and dry coughs to breakouts of rashes and even psychosis.
The team running the 'Covid-19 Symptom Tracker' app have been collecting data from people self-reporting symptoms and test results for months.
Healthy children do not die of coronavirus and only those who were seriously ill before they caught the disease are at risk, a major government-funded study has confirmed.
No healthy child has died of the virus yet in the UK, researchers said.
Six children have died but all had other serious health problems such as cancer or cerebral palsy when they were struck down by Covid-19.
Research found that the risk to children is 'strikingly low', only a tiny proportion of them end up in hospital and deaths are 'exceptionally rare'.
Six children under the age of 15 have died of coronavirus in England and Wales since the start of the pandemic, along with nine 15 to 19-year-olds. This compares with 52,082 victims in all other age groups up to August 14, according to the Office for National Statistics.
Scientists led by the University of Liverpool found that one per cent of hospitalised children died, compared to a significantly higher 27 per cent of adults. This means that while one in four adults who ended up in hospital with Covid-19 died of it, only one in 100 children did.
The research, published in the prestigious British Medical Journal, comes amid a fiery debate about whether children in England should return to school in September, with critics saying there is not enough evidence they will be safe.
Parents should be reassured that their children will not be put in danger by returning to school, the scientists who led the study said.
Professor Calum Semple, an expert in outbreak medicine and child health at the University of Liverpool who led the study, said: 'Severe disease is rare and death is vanishingly rare.
'They should be confident that their children are not going to be put at direct harm by going back to school and we do know that they are harmed by being kept away from school because of the lack of