Blanching and Non-Blanching Rashes

Rashes in Children can be divided into 'blanching' and 'non-blanching'. The group called 'blanching' disappears when you press it. The group called 'non-blanching' doesn't disappear when you press it. A 'petechial' rash is a non-blanching rash that is very small, like pin pricks. How do you tell the difference?

The Glass Test. How to tell if a rash is a non-blanching rash or a blanching rash.

The Glass Test

The way to tell if a rash is blanching or non-blanching is to place a clear drinking glass over the rash and press down. You can see that both the blanching and the non-blanching rash look exactly the same without the glass.

  1. Press glass over rash.
  2. If it disappears, it is blanching.
  3. If you can still see it, it is a non-blanching rash.

The glass test. A blanching rash. A blanching rash

The glass test. A blanching rash disappears when you press a glass on it.Press a glass against a blanching rash and it disappears, you can no longer see it

The glass test. A non-blanching rash looks the same as a blanching rash.A non-blanching rash

The Glass Test. You can still see a blanching rash when you press a glass over it.Press a glass against a non-blanching rash and it doesn't disappear, you can still see it

Some non-blanching rashes are not serious. For example, many children get little spots around their eyes when they vomit.

However, a non-blanching rash may be a sign of serious illness so it is worth getting it checked out by your doctor.

See Also:

Signs of Serious Illness in Children and Babies. How to tell if an illness is more than just a common cold.

Rashes. A guide to what to do when your child has a rash.

Get Snotty Noses to your inbox!

Download your FREE Rash and meningitis cheat sheet


Subscribe to my newsletter and every so often I'll send you something interesting on healthy happy children, starting with your RASH and meningitis cheat sheet right now

I'll never spam you. Feel free to unsubscribe at any time.