Skip to main content

Primary delusional parasitosis treated with olanzapine

  • Roland W. Freudenmann (a1), Carlos Schönfeldt-Lecuona (a1) and Peter Lepping (a2)

Delusional parasitosis (DP) is a rare psychiatric disorder, predominantly observed in middle aged and elderly patients. It can manifest itself as an isolated delusional disorder (primary DP), as a symptom of another psychiatric disorder or as an organic or toxic psychosis. The typical antipsychotic pimozide was traditionally considered to be the gold standard for treating DP. Compared with pimozide, atypical antipsychotics have many advantages in terms of tolerability, but their effectiveness has only been shown in a few case reports, which do not differentiate between primary and other forms of DP.

We present the case of a 77-year-old woman with primary DP who responded markedly to the atypical antipsychotic olanzapine (2.5 mg daily). She was treated in a psychiatric outpatient department with a follow-up period of 3.5 years. This is the first report of a successful olanzapine mono-therapy in primary DP in such a setting and the longest follow-up period ever reported. The need for maintenance treatment was demonstrated. Olanzapine in age-adapted doses should be considered as an alternative treatment. This paper also provides a review of all published cases in which primary DP was treated with atypical antipsychotics.

Corresponding author
Correspondence should be addressed to: Dr. R. Freudenmann, University of Ulm, Dept. of Psychiatry, Leimgrubenweg 12–14, 89075 Ulm, Germany. Phone: +49 731 500 61558; Fax: +49 731 500 61402. Email:
Hide All
Arnold, L. M. 2000. Psychocutaneous disorders. In Sadock, B. J. and Sadock, V. A. (eds.), Kaplan and Sadock's Comprehensive Textbook of Psychiatry. 7th edition on CD-ROM. (Chapter 25.7), Philadelphia, PA: Lippincott Williams and Wilkins.
AwD. C., D. C., Thong, J. Y. and Chan, H. L. 2004. Delusional parasitosis: case series of 8 patients and review of the literature. Annals of the Academy of Medicine, Singapore, 33, 8994.
DriscollM. S., M. S., RotheM. J., M. J., Grant-Kels, J. M. and Hale, M. S. 1993. Delusional parasitosis: a dermatologic, psychiatric, and pharmacologic approach. Journal of the American Academy of Dermatology, 29, 10231033.
Freudenmann, R. W. 2002. Delusions of parasitosis: an up-to-date review. Fortschritte der Neurologie Psychiatrie, 70, 531541.
Freudenmann, R. W. 2003. A case of delusional parasitosis in severe heart failure. Olanzapine within the framework of a multimodal therapy. Der Nervenarzt, 74, 591595.
Freudenmann, R. W. and Schönfeldt-Lecuona, C. 2005. Delusional parasitosis: treatment with atypical antipsychotics [Letter]. Annals of the Academy of Medicine, Singapore, 34, 141142.
FreyneA., A., Kenny, E. and Cooney, C. 1999. Delusions of infestation: a case report of response to risperidone. Irish Medical Journal, 92, 435.
Frithz, A. 1979. Delusions of infestation: treatment by depot injections of neuroleptics. Clinical and Experimental Dermatology, 4, 485488.
Gallucci, G. and Beard, G. 1995. Risperidone and the treatment of delusions of parasitosis in an elderly patient. Psychosomatics, 36, 578580.
Hamann, K. and Avnstorp, C. 1982. Delusions of infestation treated by pimozide: a double-blind crossover clinical study. Acta Dermato-Venereologica, 62, 5558.
KimC., C., KimJ., J., Lee, M. and Kang, M. 2003. Delusional parasitosis as “folie à deux.” Journal of Korean Medical Science, 18, 462465.
Kumbier, E. and Kornhuber, M. 2002. Delusional ectoparasitic infestation in multiple system atrophy. Der Nervenarzt, 73, 378381.
Le, L. and Gonski, P. N. 2003. Delusional parasitosis mimicking cutaneous infestation in elderly patients. Medical Journal of Australia, 179, 209210.
LeppingP., P., Gil-Candon, R. and Freudenmann, R. W. 2005. Delusional parasitosis treated with amisulpride. Progress in Neurology and Psychiatry, 9, 1216.
Makhija, M. and Bhalerao, S. 2004. Reconsidering pimozide for new-onset delusions of parasitosis. Canadian Journal of Psychiatry, 49, 643644.
Munro, A. 1982. Delusional Hypochondriasis. A Description of Monosymptomatic Hypochondriacal Psychosis (MHP). Clarke Institute of Psychiatry Monograph Series. Toronto: Department of Psychiatry, University of Toronto.
NicolatoR., R., CorreaH., H., Romano-Silva, M. A. and TeixeiraA. L., Jr. A. L., Jr. 2006. Delusional parasitosis or Ekbom syndrome: a case series. General Hospital Psychiatry, 28, 8587.
PacanP., P., Reich, A. and Szepietowski, J. C. 2004. Delusional parasitosis successfully controlled with risperidone – two case reports. Dermatology and Psychosomatics, 5, 193195.
SlaughterJ. R., J. R., ZanolK., K., Rezvani, H. and Flax, J. 1998. Psychogenic parasitosis: a case series and literature review. Psychosomatics, 39, 491500.
Trabert, W. 1995. 100 years of delusional parasitosis. Meta-analysis of 1,223 case reports. Psychopathology, 28, 238246.
Ungvari, G. 1984. Behandlung des Dermatozoenwahns durch Neuroleptika. Psychiatrische Praxis, 11, 116119.
Ungvari, G. and Vladar, K. 1986. Pimozide treatment for delusion of infestation. Activitas Nervosa Superior (Prague), 28, 103107.
van Vloten, W. A. 2003. Pimozide: use in dermatology. Dermatology Online Journal, 9, 3.
WenningM. T., M. T., DavyL. E., L. E., Catalano, G. and Catalano, M. C. 2003. Atypical antipsychotics and the treatment of delusional parasitosis. Annals of Clinical Psychiatry, 15, 233239.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

International Psychogeriatrics
  • ISSN: 1041-6102
  • EISSN: 1741-203X
  • URL: /core/journals/international-psychogeriatrics
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed