The six-year-old yesterday lost his battle with meningo-coccal septicaemia blood poisoning.
His parents David, 44, and Angela, 39, created a page on the social networking website Facebook in October to keep friends and family updated on his condition, and it has since been "liked" by more than 45,000 people.
It had been hoped that Caden, of Cleland, North Lanarkshire, while very ill, would survive the illness.
But last night his father left a heart-breaking update.
He wrote: "Dear friends, Caden Riley Beggan. Born 29th September, 2006. Died 20th November, 2012-in Mummy and Daddy's arms."
Last night thousands of users began posting tributes on the page.
Danielle Jones said: "Know that you touched so many people's hearts with your diary of Caden's fight! Every one of them is grieving with you now."
Caden was taken to Wishaw General and transferred to Yorkhill Children's Hospital in Glasgow last month as he fought the infection.
In a post on the site at the weekend, graphic designer David revealed that Caden, who has two brothers, Declan, 12, and Ethan, 3, was preparing for surgery on Monday.
But concern had grown when no post was made on Monday.
Last night head teacher Pat Ashworth, of Caden's school, Ladywell Primary said: "The whole school is terribly shocked at Caden's tragic death."
Last Saturday, the Evening Times told how First Bus painted one of its buses pink to help highlight Caden's battle.