The school's principal, Ms Richel Long, has written to all parents and said the school is liaising with the HSE on the matter.
A group of students visited the country from 12-17 of February on a school tour, some days before quarantines and other measures were put in place following an outbreak of cases of coronavirus in the country.
The number of people in Italy infected with the coronavirus has increased by 45% in the last day, with the death toll rising to 11, officials said.
Italian authorities reported 322 confirmed cases of the virus - 100 more than a day earlier.
A letter was sent home with Christ King students today urging students to seek medical advice if they feel unwell.
"The Principal has been in contact with the HSE and the advice to date is if your daughter is feeling unwell to contact your doctor for medical advice," Ms Long wrote. "The HSE have informed the public through their website symptoms may take up to 14 days to appear and should your daughter present with a cough, shortness of breath, breathing difficulties or a fever to please seek medical advice.
This evening the Department of Education and Skills has updated information for schools on Covid-19; following a meeting of the National Public Health Emergency Team.
The Department said anyone who has been to affected regions in the last 14 days and has a cough, shortness of breath, breathing difficulties or fever should self-isolate and phone their GP immediately.
Anyone who has travelled from the affected regions and has no symptoms should visit www.HSE.ie for advice.