Apparent cyclic vaginal bleeding in a child: factitious disorder.

A 20-mo-old girl was brought to our department by her mother because of breast enlargement. She was diagnosed with premature thelarche. One month later, she returned to our hospital with a complaint of vaginal bleeding. During the subsequent 6 mo, her vaginal bleeding recurred every month while her breast development disappeared. We performed laboratory tests and imaging. At the end of 6 mo, we realized that her mother's menstrual bleeding and the patient's blood staining were concurrent. The mother confessed applying her vaginal flow to her daughter's underwear. Factitious disorder should be included in the differential diagnosis of unexplained vaginal bleeding in childhood.