Named for Baron von Munchausen, who told fanciful tales about his travels and exploits, Munchausen syndrome is the fabrication or induction of illness in the self in order to get attention; it results in needless medical investigation and treatment [1,2]. Munchausen syndrome by proxy (also known as factitious disorder by proxy, Meadow syndrome, proxy factitia, and erroneously as Polle syndrome ) was first described in 1977  and consists of fabricating or inducing illness in a child in order to get attention.
Munchausen syndrome is a psychiatric illness. In contrast, Munchausen syndrome by proxy is a psychiatric illness and an insidious form of child abuse [5-8]. The American Professional Society on the Abuse of Children (APSAC) multidisciplinary task force on Munchausen by proxy (MBP) describes two components: the adult perpetrator (who is diagnosed with factitious disorder by proxy), and the child victim, who suffers from pediatric condition (illness, impairment, or symptom) falsification [9,10].
The epidemiology, clinical features, evaluation, and management of MBP will be reviewed here. Munchausen syndrome and other forms of physical child abuse and neglect are discussed separately. (See "Factitious disorder and Munchausen syndrome" and "Child neglect and emotional abuse" and "Physical abuse in children: Epidemiology and clinical manifestations" and "Physical abuse in children: Diagnostic evaluation and management" and "Child abuse: Evaluation and diagnosis of abusive head trauma in infants and children".)
Munchausen by proxy (MBP) is a relatively rare form of child abuse which poses a significant danger of morbidity or mortality to the affected child . In the largest prospective series of cases, the annual incidence of MBP, nonaccidental poisoning, and nonaccidental suffocation in the United Kingdom and Ireland was determined to be 0.5/100,000 in children younger than 16 years and 2.8/100,000 in children younger than one year . A similar annual incidence (2.0 per 100,000 in children younger than 16 years) was determined in New Zealand by surveying pediatricians .
In the prospective study described above, 128 cases of MBP were detected in two years . Most of the affected children (77 percent) were younger than five years (median age 20 months). Hospitalization was required in 95 percent of cases; length of stay was between 7 and 30 nights in 41 percent, and >30 nights in 23 percent . Mortality rates of 9 to 10 percent have been reported [11,13]. Death is often caused by poisoning or suffocation . The perpetrator was the mother in 85 percent of cases, the father in 5 percent, another adult in 1 percent, and uncertain in 9 percent.