Li Xiaoyuan, from Fengkai in southern China, had a small birthmark on her back just months ago, which has since grown to cover her entire back and parts of her arms and face, The Sun reports.
"Doctors told us it was just how a birthmark even when it started spreading but now it covers half her body," her father Li Yan was quoted as saying.
"None of the other children want to play with her, they are calling her cat-girl and are really mean."
Her mother Li Jian said it broke her heart to see her daughter suffer like this.
A surgeon at Zhaoqing City Dermalogical l Hospital in China's Guangdong province said Li Xiaoyuan may have a rare skin disease that makes normal moles run amok.
Dr Lou Zhongquan said laser surgery could have been used if the skin problem was smaller, but there would be a significant chance of post surgery haemorrhage if Li was operated on.