Seth has "bubble boy" disease and he's got a favour to ask you.

Wear yellow to support a little boy who is facing another year in hospital.

Supporters around the world will be wearing yellow today, Friday 27 March, in support of one little boy called Seth Lane, who suffers from a rare condition that leaves him with zero immune system.

The five-year-old boy from Corby in the United Kingdom, has a condition called Severe Combined Immunodeficiency (SCID), more commonly known as “bubble boy” disease.

The disease means Seth must live in a sterile environment to avoid getting sick. He cannot be exposed to anything in the outside world because the parts of his body that should protect it don’t work the way they do in other children.

It also means he’s spent most of his short-life in hospital and in isolation.

Seth Lane. Image via Facebook.

In order to survive, Seth needs a bone marrow transplant. This will be his second major operation after the first transplant was unsuccessful. As he now also faces a further 12 months in hospital to recover from the impending surgery, his mother Leanne wanted to find a way to garner some support for her young son.

Read more: Internet campaign to support young boy with rare disease.

She posted the below video asking the public to #WearYellowForSeth and show their support on social media.

She hopes she can share a few messages with him, to lift his spirits and remind him he isn’t alone.

The campaign has gone viral with the video being viewed more than eight million times. Seth has received thousands of messages including support from celebrities like Ashton Kutcher and Montel Williams.

Seth’s mum Leanne said the idea of #WearYellowForSeth came to her back in 2010, when a friend battling leukaemia told her that yellow signifies a strong immune system.

The family is not asking for donations, just messages they can share with Seth. Currently, the only other child Seth has contact with is his younger brother, Hugo, who is five months old.

So if you have a young child at home who might like a pen pal for the day? Seth sure would love the company and the support.