Munchhausen syndrome by proxy (MSBP) differs from other forms of parenting disorder in that the offending parent is almost always the mother, she usually appears to be a model mother, there is little or no indication of family discord, and the abusive behavior is clearly premeditated, not impulsive, and not in reaction to the child's behavior.
Fabricated illness is the more frequent form of MSBP. The parent may claim that their child is ill, when the child is not.
For example, a parent might claim their child is having seizures when the child is not. Or a parent may allege that their child is passing blood in its urine and provides urine samples suggesting this is so, whereas the parent has pricked their own finger and dripped blood into the urine sample. Induced illness is the less frequent but more dangerous form of MSBP. This involves the parent inflicting damage on their own child. For instance, the parent may inject air under the child's skin or feed the child too much salt and make them sick. Some of these child victims die at the hands of their parents. Claims have been made that MSBP is more common than is generally thought or that it is rare or even that it does not exist. However, cases of MSBP have been documented beyond a reason doubt and we have ourselves seen several cases. In all likelihood, MSBP is probably uncommon but in truth the frequency of MSBP is uncertain. The psychological basis for MSBP is also uncertain. In some cases, there is a misdirected parental desire for attention. In other cases, the parent may have a history of mental illness. Or the parent may have been abused as a child themselves. We believe that the causes of MSBP may well be heterogeneous and vary from case to case. The term Munchhausen syndrome by proxy was coined by the British pediatrician Roy Meadow in a report describing two cases of the condition in 1977. Other names for the condition include fabricated illness by proxy, factitious disorder by proxy. Meadow syndrome, and Polle syndrome (after the fictional Baron Munchhausen's only child who died at a year of age).