Delusional parasitosis may occur on its own or as a complication
of another disorder.
It's enough to make your skin crawl, just thinking about it:
insects, worms, fungi, or other pathogens colonizing a person's
body. When there is no proof of actual infestation, however, the
problem may be delusional parasitosis.
This poorly understood disorder has gone by different names over
the years, including Ekbom's syndrome (named for the first doctor
to identify the phenomenon as a disorder), organic hallucinosis,
unexplained dermopathy, and delusional infestation. The most
recent manifestation of delusional parasitosis may be Morgellons,
in which people believe they have been infested with fibers,
threads, and other inanimate material. None of these names
appears in the Diagnostic and Statistical Manual of
Mental Disorders, Fourth Edition (DSM-IV). Instead,
delusional parasitosis most closely resembles what
the DSM-IV categorizes as delusional disorder,
Defined most simply, hallucinations are
false perceptions, and delusions are
false beliefs. Delusional parasitosis is a bit of a
hybrid. The phenomenon involves both
perception and belief. And the disorder's
symptoms may be based on a misinterpretation of real sensations.
This disorder may thus be related
to paresthesia (Greek for abnormal sensation),
akin to the feeling of "pins and needles."
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