Delusional parasitosis
Delusional parasitosis | |
---|---|
Other names | Delusional infestation or Ekbom's syndrome[1] |
Specialty | Psychiatry, dermatology |
Delusional parasitosis (DP) is a
Delusional parasitosis is classified as a
The condition is rare, and is observed twice as often in women as men. The average age of people with the disorder is 57. An alternative name, Ekbom's syndrome, honors the neurologist Karl-Axel Ekbom, who published seminal accounts of the disease in 1937 and 1938.[1]
Classification
Delusional infestation is classified as a
Morgellons is a form of delusional parasitosis in which people have painful skin sensations that they believe contain fibers of various kinds; its presentation is very similar to other delusional infestations, but people with this self-diagnosed condition also believe that strings or fibers are present in their skin lesions.[1][2]
Delusory cleptoparasitosis is a form of delusion of parasitosis where the person believes the infestation is in their dwelling, rather than on or in their body.[3]
Signs and symptoms
People with delusional parasitosis believe that "parasites, worms, mites, bacteria, fungus" or some other living organism has infected them, and reasoning or logic will not dissuade them from this belief.
A "preceding event such as a bug bite, travel, sharing clothes, or contact with an infected person" is often identified by individuals with DP; such events may lead the individual to misattribute symptoms because of more awareness of symptoms they were previously able to ignore.[1] Nearly any marking upon the skin, or small object or particle found on the person or their clothing, can be interpreted as evidence for the parasitic infestation, and individuals with the condition commonly compulsively gather such "evidence" to present to medical professionals. This presentation is known as the "matchbox sign", "Ziploc bag sign" or "specimen sign", because the "evidence" is frequently presented in a small container, such as a matchbox.[1][4] The matchbox sign is present in five to eight out of every ten people with DP.[1] Related is a "digital specimen sign", in which individuals bring collections of photographs to document their condition.[1]
Similar delusions may be present in close relatives—a shared condition known as a folie à deux—that occurs in 5–15% of cases and is considered a shared psychotic disorder.[4] Because the internet and the media contribute to furthering shared delusions, DP has also been called folie à Internet; when affected people are separated, their symptoms typically subside, but most still require treatment.[4]
Approximately eight out of ten individuals with DP have
A 2011 Mayo Clinic study of 108 patients failed to find evidence of skin infestation in skin biopsies and patient-provided specimens; the study concluded that the feeling of skin infestation was DP.[1][6]
Cause
The cause of delusional parasitosis is unknown. It may be related to excess
Diagnosis
Delusional parasitosis is diagnosed when the delusion is the only symptom of psychosis, the delusion has lasted a month or longer, behavior is otherwise not markedly odd or impaired, mood disorders—if present at any time—have been comparatively brief, and the delusion cannot be better explained by another medical condition, mental disorder, or the effects of a substance. For diagnosis, the individual must attribute abnormal skin sensations to the belief that they have an infestation, and be convinced that they have an infestation even when evidence shows they do not.[1]
The condition is recognized in two forms: primary and secondary. In primary delusional parasitosis, the delusions are the only manifestation of a psychiatric disorder. Secondary delusional parasitosis occurs when another psychiatric condition, medical illness or substance (medical or recreational) use causes the symptoms; in these cases, the delusion is a symptom of another condition rather than the disorder itself.[2] Secondary forms of DP can be functional (due to mainly psychiatric disorders) or organic (due to other medical illness or organic disease.[4] The secondary organic form may be related to vitamin B12 deficiency, hypothyroidism, anemia, hepatitis, diabetes, HIV/AIDS, syphilis, or use of stimulants like methamphetamine and cocaine.[4][7]
Examination to rule out other causes is key to diagnosis.
Differential
Delusional parasitosis must be distinguished from scabies, mites, and other psychiatric conditions that may occur along with the delusion; these include schizophrenia, dementia, anxiety disorders, obsessive–compulsive disorder, and affective or substance-induced psychoses or other conditions such as anemia that may cause psychosis.[5]
Treatment
As of 2019, there have not been any studies that compare available treatments to placebo.[9] The only treatment that provides a cure, and the most effective treatment, is low doses of antipsychotic medication. Cognitive behavioral therapy (CBT) can also be useful. Risperidone is the treatment of choice.[1] For many years, the treatment of choice was pimozide, but it has a higher side effect profile than the newer antipsychotics.[5] Aripiprazole and ziprasidone are effective but have not been well studied for delusional parasitosis. Olanzapine is also effective. All are used at the lowest possible dosage, and increased gradually until symptoms remit.[1]
People with the condition often reject the professional medical diagnosis of delusional parasitosis, and few willingly undergo treatment, despite demonstrable efficacy, making the condition difficult to manage.[1][2][10] Reassuring the individual with DP that there is no evidence of infestation is usually ineffective, as the patient may reject that.[5] Because individuals with DP typically see many physicians with different specialties, and feel a sense of isolation and depression, gaining the patient's trust, and collaborating with other physicians, are key parts of the treatment approach.[4] Dermatologists may have more success introducing the use of medication as a way to alleviate the distress of itching.[4] Directly confronting individuals about delusions is unhelpful because by definition, the delusions are not likely to change; confrontation of beliefs via CBT is accomplished in those who are open to psychotherapy.[5] A five-phase approach to treatment is outlined by Heller et al. (2013) that seeks to establish rapport and trust between physician and patient.[1][11]
Prognosis
The average duration of the condition is about three years.[1] The condition leads to social isolation and affects employment.[1] Cure may be achieved with antipsychotics or by treating underlying psychiatric conditions.[1]
Epidemiology
While a rare disorder, delusional parasitosis is the most common of the
It is observed twice as often in women than men. The highest incidence occurs in people in their 60s, but there is also a higher occurrence in people in their 30s, associated with substance use.[1] It occurs most often in "socially isolated" women with an average age of 57.[4]
Since the early 2000s, a strong internet presence has led to increasing self-diagnosis of Morgellons.[1]
History
Karl-Axel Ekbom, a Swedish neurologist, first described delusional parasitosis as "pre-senile delusion of infestation" in 1937.[1] The common name has changed many times since then. Ekbom originally used the German word dermatozoenwahn, but other countries used the term Ekbom's syndrome. That term fell out of favor because it also referred to restless legs syndrome (more specifically termed Willis–Ekbom disease (WED) or Wittmaack-Ekbom syndrome).[12][13] Other names that referenced "phobia" were rejected because anxiety disorder was not typical of the symptoms.[13] The eponymous Ekbom's disease was changed to "delusions of parasitosis" in 1946 in the English literature, when researchers J Wilson and H Miller described a series of cases, and to "delusional infestation" in 2009.[1][14] The most common name since 2015 has been "delusional parasitosis".[2]
Ekbom's original was translated to English in 2003; the authors hypothesized that James Harrington (1611–1677) may have been the "first recorded person to suffer from such delusions when he 'began to imagine that his sweat turned to flies, and sometimes to bees and other insects'."[15]
Morgellons
Mary Leitao, the founder of the Morgellons Research Foundation,
An active online community has supported the notion that Morgellons is an infectious disease, and propose an association with Lyme disease. Publications "largely from a single group of investigators" describe findings of spirochetes, keratin and collagen in skin samples of a small number of individuals; these findings are contradicted by the much larger studies conducted by the CDC.[2]
Society and culture
Shelomi published another study in 2013 of what he called scientific misconduct when a 2004 article in the Journal of the New York Entomological Society included what he says is photo manipulation of a matchbox specimen to support the claim that individuals with DP are infested with
See also
References
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- ^ a b c d e f g h i j k l Suh KN (June 7, 2018). "Delusional infestation: Epidemiology, clinical presentation, assessment and diagnosis". UpToDate. Wolters Kluwer. Retrieved March 8, 2020.
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- ^ Harlan C (July 23, 2006). "Mom fights for answers on what's wrong with her son". Pittsburgh Post-Gazette. Retrieved August 4, 2007.
- ^ DeVita-Raeburn E (March–April 2007). "The Morgellons mystery". Psychology Today. Retrieved May 8, 2015.
- ^ Browne T (1690). "A Letter to a Friend". James Eason, University of Chicago.
- ^ Schulte B (January 20, 2008). "Figments of the Imagination?". Washington Post Magazine. p. W10. Retrieved June 9, 2008.
- ^ "Unexplained dermopathy (aka "Morgellons"), CDC Investigation". Centers For Disease Control. November 1, 2007. Archived from the original on June 3, 2016. Retrieved May 9, 2011.
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- ^ ISBN 978-0199930197.
- ^ Traver J (February 1951). "Unusual scalp dermatitis in humans caused by the mite, Dermatophagoides (Acarina, epidermoptidae)" (PDF). Proceedings of the Entomological Society of Washington. 53 (1).
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- ISSN 0146-6429. Archived from the original(PDF) on 2017-12-15. Retrieved 2020-08-04.
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Further reading
- Halvorson CR (October 2012). "An approach to the evaluation of delusional infestation". Cutis (Review). 90 (4): E1–E4. PMID 24005827.
- Simpson L, Baier M (August 2009). "Disorder or delusion? Living with Morgellons disease". Journal of Psychosocial Nursing and Mental Health Services (Case report and review). 47 (8): 36–41. PMID 19681520.