Dr Obaghe Edeghere from the UKHSA said the ongoing rise in cases scarlet fever and strep throat (a sore throat caused by the strep A illness) is "understandably concerning for parents".
But he stressed the condition "can be easily treated with antibiotics and it is very rare that a child will go on to become more seriously ill".
"Over the winter, there are lots of illnesses circulating that can make children unwell and so it is important to avoid contact with other people if you are feeling unwell, wash your hands regularly and thoroughly and catch coughs and sneezes in a tissue", Dr Edeghere added.
He also emphasised parents must make sure they speak to a healthcare professional if they believe their child is becoming more ill, for example if they are:
feeding or eating less than normal
have a high temperature that won't go down
are very hot and sweaty
seem more tired or irritable than normal.
Other key comparisons from the UKHSA data show that there have been 102 iGAS cases in children aged five to nine, compared to 117 across the 2017 to 2018 season.
Of 122 deaths across all age groups in England this season, 49 were in the over-75s and 20 were children younger than 10. In 2017 to 2018 there were 355 deaths in total - including 27 children.
On Wednesday, Scotland's national clinical director Professor Jason Leitch said the country was experiencing the highest number of Strep A infections since 2017 - but added the deaths of two children there this year so far was "not unusual".