Ollerton Primary School has confirmed there were three cases of Scarlet fever last week at the school.
While one child had returned after a short period at home, while two siblings remained absent as a precaution.
Headteacher Carl Braithwaite said: “There is a bit of a crisis in the region at the moment. We have sent a letter to parents telling them what to look out for.
“People should seek medical attention if they have any concerns.”
The infection affects 4–8-year-old children. Symptoms include sore throat, fever and a red rash.
It is treated with antibiotics.