Mariah Carey's nose ate away her face in her new movie.

The Hero singer had to don prosthetic features for her role as a dowdy social worker in Precious but suffered an intense allergic reaction to the materials used to create it.

She said: "We tried to do a prosthetic nose but it started to make me break out so we had to rip it off.

"After that I was all red and swollen. I have such sensitive skin that it started to eat away all my face. It was like, I won't be doing this.

"But it did have an effect on my look in the film, unglamorous, not pretty at all."

Mariah, 40, recently revealed she struggled so much with the unglamorous role she landed herself in trouble with the film s director after he caught her trying to put make-up on.

She said: "It was tough. I am so used to the music world which is so different with the cameras, the lighting, the angles and this and that. At one point the director caught me trying to put blusher on and he said, What are you doing? What are you doing? He was not going for it."

However, Mariah, who is married to rapper-and-presenter Nick Cannon, soon got used to shunning her usual beauty regime and says the movie has left her more relaxed about her looks.

She added: "I feel better about myself when I am just normal at my house walking past the mirror without make-up on now. I m like, 'well, I ve looked worse!'"