Credit: Jason LaVeris/FilmMagic

Nicole Richie has checked herself into a Los Angeles hospital.

A rep for the star tells, "Nicole has checked into Cedars-Sinai where she is being treated for pneumonia. She is doing well."

Citing illness, Richie, 28, bowed out of the Nov. 10 launch of her House of Harlow jewelry at Bebe in L.A.

In September, she gave birth to son Sparrow, her second child with Joel Madden; daughter Harlow is 22 months old.