Delusional parasitosis or Ekbom's Syndrome is a rare disorder in which a person holds a delusional belief they are infested with parasites.

It is not to be confused with Wittmaack-Ekbom or restless legs syndrome. Unfortunately, this is also referred to in short as 'Ekbom's Syndrome' leaving the audience to have to infer which from the context.

It is named after a Swedish neurologist who published seminal accounts of the disease in 1937 and 1938.

The sufferer typically reports parasites to exist under the skin, around or inside body openings, in the stomach or bowels and may or may not include a belief that the parasites infest the sufferer's home, surroundings or clothing.

A person holding such a belief may approach doctors or dermatologists asking for treatment for the supposed infestation, and will often bring small particles, dust, skin flakes and other material for the doctor to inspect. Since the material may be carried in an envelope or matchbox, this presentation is known as the 'matchbox sign'.

Stimulant drug abuse can lead to delusional parasitosis. For example, excessive cocaine use can lead to an effect nicknamed 'cocaine bugs' where the affected person believes they have, or feels parasites crawling under their skin.

An excellent fictional account of delusional parasitosis is given in the opening chapter of Philip K. Dick's novel A Scanner Darkly.

See also: delusion, delusional disorder, psychosis

External links and references

  • Enoch, D. & Ball, H. (2001) Ekbom's Syndrome (Delusional parasitosis). In Enoch, D. & Ball, H. Uncommon psychiatric syndromes (Fourth edition) pp209-223. London: Arnold. ISBN 0340763884
  • Ekbom, K.A. (2003) The pre-senile delusion of infestation (Classic text no. 54). History of Psychiatry, 14 (2), 229-256.