One of the common queries for the public health team is in regard to “green noses” and whether children with green noses should be excluded from the early childhood centre.

What causes a runny nose?

Children can have a runny nose for several reasons:

  • Allergy
  • Sudden change in temperature or very dry air
  • Infection - viral or bacterial

Viral and bacterial infections

The most common cause of a runny nose is a viral upper respiratory tract infection (URTI), often referred to as a ‘common cold’. Young children contract 6-9 colds each year. The majority of viral infections will resolve on their own and typically last 5-10 days. Common symptoms include nasal discharge, nasal congestion, cough and fever.

Mucus sitting in the nose and chest during a cold is a breeding ground for bacteria to grow in, so it is important to encourage children to blow their noses. Sometimes, the bacteria can grow and cause a secondary bacterial infection (the primary infection being the virus). This can occur in the sinuses, the chest, or the ears.

The problem is that the common cold virus can cause green nasal secretions and a phlegmy/congested sounding cough. This however does not signify that a bacterial infection is present. This should be determined by a doctor who will make a diagnosis based on how long the child has been unwell, how bad the symptoms have been and other examination or investigation. This will help to determine whether the infection is likely viral, bacterial or if the symptoms are due to an allergy.


What does the colour mean?

The colour of nasal discharge may change during the course of the cold from clear to yellow or green. This colour change is linked to the recruitment of white blood cells, which help fight off infection.

So the colour of the discharge describes HOW the body is dealing with the infection as opposed to WHAT the body is dealing with.


Exclusion period

For children with new symptoms:

Children or staff with new flu-like symptoms should not be attending an early childhood centre. This includes coughing/sneezing, sore throat, runny nose, nasal congestion, headache, or fever. If the runny nose is an ongoing concern, please see the section below.

A sick person can still be infectious even when they appear well and need to stay home from their centre until 2 days (48hrs) after all signs of flu have gone. In general, a flu-like illness lasts 3-4 days but it can be up to 7 days.

People worried about their symptoms or who have an underlying condition that makes them vulnerable to severe respiratory illness, for example - asthma, can telephone Healthline 0800 611 116 or their family doctor for further advice.

If children or staff become unwell with flu-like symptoms while at their centre, they need to go home to be cared for and should be tested for COVID-19. While waiting to go home they need to be kept in an area away from others and monitored until they leave the centre. Staff caring for children with flu-like symptoms can protect themselves by wearing gloves, an apron and a facemask if the child is coughing. Hands need to be washed regularly during contact with a sick person.

COVID-19 Exclusion period

Covid-19 is a highly contagious disease that affects the lungs, airways and other organs. Some people with COVID-19 can get very sick, and some people severely sick.  If a child or staff test positive for COVID-19, we recommend they isolate for at least 5 days, even if they only have mild symptoms.

If your child tests positive for COVID-19, inform the centre, register the positive test on the My Covid Record website and follow the advice available at

A child should not attend the centre if:

  • A Medical Professional or Regional Public Health has advised them that they must remain at home.
  • They have ongoing symptoms and it has not been 48 hours since they have completely resolved.
  • They test positive for COVID-19 and are not well.

For children with a persistent runny nose:

Children with symptoms due to allergies or another non-infectious cause (as diagnosed by a doctor) do not need to be routinely excluded from the early childhood centre, if there has been no change to their symptoms.

However if they have new or worsening flu-like symptoms concerning for infection, they should follow the exclusion advice as above (go home until recovered and symptom free for 48 hours).

Some considerations for management of persistent runny nose:

Think about the social impact for the child with the persistent runny nose. This is unpleasant for the child, the teacher and peers. Ask yourself:

  • Is this child included in group activities?”
  • What kind of social interactions does he/she have with teachers? 

A lack of inclusion by peers and teachers will not create a sense of wellbeing and belonging.

A child may have a persistent green runny nose but may still be able to take part comfortably in the programme of activities, and may not require any extra attention. Early childhood teachers can usually make this judgement based on their knowledge of individual children.

If you are worried about a child who often has a green runny nose or appears consistently congested, discuss concerns with the parents/caregivers and recommend the child see a doctor.

Download printable factsheet

Last updated 26 April 2024.