“My friend’s son was born with EB,” the actress tells PEOPLE in this week’s issue. “I’ve been a part of it since then. He’s 11 now. There is no cure for this disease. It’s just such a horrible thing.”
The condition, which usually strikes babies and children, causes painful skin blisters; there is little hope for those affected beyond the age of 30.
“You have no choice to feel for these kids,” says Cox, 51, who has an 11-year-old daughter, Coco. “The disease is very rare so need to bring awareness.”
The kids fighting EB, who are often called Butterfly Children because of the fragility of their skin, will be honored at the third annual Rock4EB! on Sunday, where Ed Sheeran will perform.
“The kids run around and have a good time,” says Cox. “They’re being honored. It’s for them.”
But she’ll leave the entertainment to the professionals: “No singing for me. There’s no good singing coming out of my mouth!”