Most people suffer chickenpox as a child and barely remember the illness.

But a gruesome video shows how unpleasant it can be to suffer the virus as an adult.

The clip shows a 32-year-old, from London, whose entire body is covered in huge white pustules which look painful and itchy.

He holds a camera close to his skin to reveal the enormous blisters.

There are angry, pus-filled whiteheads all over his back, and his shoulders are completely covered in red scabs.

The man, who uploaded the video to YouTube under the name Harris82, does not identify himself by filming his face, although he does pan over his spot-covered forehead.

Chickenpox, known medically as varicella, is highly contagious and can easily be caught from someone infected.

It causes a rash of red, itchy spots that turn into fluid filled blisters – as seen in the video – which crust over to form scabs and eventually drop off.

In childhood, it is a mild illness that is so common more than 90 per cent of adults are immune because they’ve had it before.

In adults, chickenpox tends to be much more severe and they have a higher risk of developing complications.

The 32-year-old man uploaded a video showing a horrific case of adult chickenpox in which his entire body is covered in huge, white, fluid-filled blisters

Adults with the illness may be prescribed an antiviral medicine known as Aciclovir, which needs to be started within 24 hours of the rash appearing.

It does not cure chickenpox, but makes the symptoms less severe.

There is also a vaccine for the illness, but it is only offered to children and adults who are particularly vulnerable to chickenpox complications.