Munchausen's Syndrome is a
psychiatric disorder in which the patient pretends to have an illness, in order to receive medical tests and treatment, frequently surgical procedures.
On the other hand, Munchausen's by Proxy Syndrome (MSP) differs in that a carer (frequently a parent) will attribute symptoms to those in their care, thereby subjecting them to unnecessary medical tests and/or surgical procedures. In some cases, the carer will also inflict physical injury on the victim to get medical attention. In some recent cases in the UK (notably the nurse Beverley Allitt), the patient is in one of the caring professions.
In order to be effective at obtaining treatment for their charges, sufferers must have some medical knowledge (to be able to come up with convincing symptoms requiring professional attention). Additionally, they will appear to be both friendly and co-operative with health professionals, and concerned for the welfare of those in their care. A common strategy from the MSP sufferer is to describe symptoms of an ailment which is not readily apparent - one such is apnea (a temporary cessation of breathing). Some psychiatrists believe that this is an attention-seeking behavior.
If initial complaints are not taken seriously, the patient may exacerbate the situation by harming their charge - in the case of a parent, by causing some injury in keeping with the described symptoms, or in the case of health professionals, by administering drugs or medication.
As MSP progresses, a pattern may develop of serial visits from parents, which can alert health professionals, but in all too many cases, children and patients have died, effectively at the hands of the MSP sufferer.
Medical professionals are always reluctant to suspect MSP - they are trained and conditioned to believe both to parents and fellow professionals, each of whom should demonstrate a natural concern.
In the case of the Nottingham nurse Beverley Allitt, she was convicted in 1993 of directly causing the deaths of four patients, and injuring nine others. She achieved this by interfering with medical equipment and administering drugs, notably insulin.
In another case in New York, the Hoyte family had 5 recurrent deaths in the children that were thought to be 'cot deaths' (SIDS).
It is also worth noting that the film The Sixth Sense makes reference to MSP, in that one scene showed a mother putting something in her daughter's soup, and funeral goers were overheard to say that "another little one's getting sick". Cole Sear helps out by giving a video tape of the poisoning to the girl's father. Thanks to Chattering Magpie for pointing this out to me.
http://www.panix.com/~dangelo/sixt.html
http://www.ashermeadow.com/