Whenever children are unwell they should rest at home and refrain from coming to school. First because the child's immunity goes down and it feels weak. Besides he/she is irritable because he/she cant communicate what's happening to him/her_ Secondly if the child has contracted any infectious diseases other children could get infected-
Your Children's Health is Important than their Grades
Brad Sherman
Chicken Pox
Children are infectious in the early stages from 2 days before rash appears until all
blisters are crusted. Exclude atleast 5 days after eruption appears. Child could return when fit
Mumps
Infectious from 6 days before to 9 days after the onset of Swelling. Exclude atleast for 9 days after onset of symptoms
Measles
Until you get a medical fitness certificate or 7 days from onset of rash,
Conjunctivities
Until discharge from eyes have ceased and the eyes have cleared fully/
certificate from the doctor.