[Munchausen syndrome: update].

Munchausen's syndrome has been described by Asher (1951) on the basis of 4 remaining permanent criteria, beyond its numerous expressive symptoms. The present work describes the usual process undergoing during their contacts with hospitals, collecting diagnosis criteria and differential diagnosis. Etiology hypothesis, possibilities of treatment, will be discussed both in a reflexive and preventive perspective, regarding the very high costs thus inferred, in terms of health (of the patients and the medical teams), and of financial and legal problems.