Dr Phil Kieran: When is it safe to mix with others after chickenpox?

We all remember chickenpox from childhood. Thankfully, for most, it is a mild illness that causes a runny nose and cough, followed by an itchy rash that goes away without medical intervention. Chickenpox is a ‘vesicular’ rash, meaning it shows up as fluid-filled spots that burst. This fluid is full of chickenpox virus (varicella), so the child remains contagious while these spots are present.

As it is a viral illness, there isn’t a medication to treat it. However, you can treat the symptoms. Keep the child cool, as heat can worsen the itch. Encourage them not to scratch, as this increases the risk of scarring or severe skin infection. Use paracetamol for their temperature (ibuprofen is not recommended, as it increases the risk of skin infection). You can also get topical treatments to help with the itch.

Chickenpox is contagious two to three days before the rash starts (when it is being spread in our respiratory secretions and saliva) and remains contagious until the last lesion has scabbed over. 

This takes, on average, one to three weeks. Some childcare facilities will have policies on how long to exclude a child with chickenpox, but a strict time approach is difficult, as you don’t know when the last spots will appear and scab over.

It’s commonly believed that there is no need to worry about catching chickenpox, but it can be a serious condition. The virus can be dangerous if you contract it during pregnancy, so be cautious around those who are contagious.

If your child has stopped forming new spots and all his spots have crusted over, he is no longer contagious. But there is no way of knowing what risk factors your childminder has or whether they have a medically vulnerable person at home they can’t risk exposing to varicella.

Similarly, with a creche setting, they may have vulnerable children or staff that they need to protect.

Chickenpox can lead to serious complications, such as pneumonia, severe skin infections, and even swelling or brain injuries. Due to this and just how miserable chickenpox is, I am delighted we have started vaccinating children against this illness.