Delusional parasitosis: folie à deux and attempted murder of a family doctor.

A 58-year-old woman suffering from delusional parasitosis tried to kill her general practitioner. Her husband shared in her beliefs but lost all delusional conviction after she was compulsorily admitted to a special hospital. The case illustrates the intractable nature and potential dangerousness of some of these cases, and their affinity to paranoia.