Colin Farrell has paid a moving tribute to his close friend Emma Fogarty upon her "miracle" 40th birthday - and has revealed he is running the Dublin marathon to raise funds for an Irish charity in her honor.

Fogarty, from Co Laois, is Ireland's longest-surviving person battling epidermolysis bullosa (EB), a rare skin condition that causes extremely painful blistering of the skin in response to the slightest movements. 

When Fogarty was born, doctors said she would not live longer than a week. 

The inspirational Irish woman, however, marked her 40th birthday on June 25 and celebrated the occasion with a reception at Killashee Hotel and Spa in Co Kildare on July 23. 

Upon Fogarty's milestone birthday, Farrell has described her as the "strongest person" that he's ever met, adding that she is a "true warrior."

"Emma Fogarty is not only the strongest person I’ve ever met and a true warrior, I’m lucky enough to call her a friend," Farrell said. 

"For years now, I’ve been fortunate enough to bear witness not only to her courage and her vulnerability but her humor, her stubbornness, and her great, great heart too." 

Farrell has now revealed that he will undertake ‘Emma’s Run to 40’ by completing October’s Irish Life Dublin Marathon. 

Fogarty plans to join the Irish Oscar nominee in a wheelchair for the final stages of the 42km race. 

The Dublin native Hollywood A-lister is hoping that, with the public's help, he can raise €400,000 for Debra, the national charity helping 300 people living in Ireland with EB. 

Farrell said: “The fact that I’m getting to run the Irish Life Dublin Marathon with my friend to celebrate her 40th birthday is something I’m so excited about.

"She’s already won the whole day!” 

Fogarty appealed to Irish people to donate to Debra so that people living with EB can live the "longest, fullest life possible."

In a video shared by Debra, the duo joked that the best way to mark Fogarty's 40th birthday is to put Farrell through "four hours of pain" via the marathon.

Fogarty was born with no skin on her right arm, while 80% of her body is covered in layers of bandages to protect her from wound infection. 

Her bandages are changed every second day, taking up to four hours at a time, leaving Fogarty in excruciating pain. 

Emma Fogarty celebrating her 40th birthday.

Emma Fogarty celebrating her 40th birthday.

"The doctors said it would be better for me not to make it, because my life would be so hard," Fogarty said. 

"No one expected me to survive for this long – because people with my type of EB almost never do – but I’ve always been encouraged to be a fighter.

"Reaching 40 shouldn’t be a miracle, but right now, it is." 

Anyone interested in supporting Emma's Run to 40 initiative can do so here.