Delusional parasitosis
Encyclopedia
Delusional parasitosis is a form of psychosis
whose victims acquire a strong delusion
al belief that they are infested with parasites, whereas in reality no such parasites are present. Very often the imaginary parasites are reported as being "bugs" or insects crawling on or under the skin; in these cases the experience of the sensation known as formication
may provide the basis for this belief.
Delusional parasitosis is also sometimes referred to as "Ekbom's syndrome", named after a Swedish neurologist, Karl Axel Ekbom, who published seminal accounts of the disease in 1937 and 1938. But this name can be confusing because others use the term Ekbom's syndrome interchangeably with Wittmaack-Ekbom syndrome, another name for restless legs syndrome
(RLS). Although delusional parasitosis and RLS were both researched by Ekbom, and RLS sufferers sometimes describe some of their symptoms as if they have, for example, "ants in my veins", the similarities stop there. RLS is a physical condition with physical causes, whereas delusional parasitosis is a false belief.
The false belief of delusional parasitosis stands in contrast to actual cases of parasitosis, such as scabies
.
People with delusional parasitosis are likely to ask for help not from psychiatrists but from dermatologists, veterinarian
s, pest control
specialists, or entomologists. Because delusional parasitosis is not at all well known to non-specialists, under those circumstances the condition often goes undiagnosed, or may be incorrectly diagnosed.
or clinical depression
.
, cancer
, cerebrovascular disease
, tuberculosis
, neurological disorders, vitamin B12 deficiency
, and diabetes mellitus
. Any illness or medication for which formication
is a symptom or side effect can become a trigger or underlying cause of delusional parasitosis.
Other physiological factors which can cause formication and thus can sometimes lead to this condition include: menopause
(i.e. hormone withdrawal); allergies, and drug abuse, including but not limited to cocaine
and methamphetamine
(as in amphetamine psychosis
). It appears that many of these physiological factors, as well as environmental factors such as airborne irritants, are capable of inducing a "crawling" sensation in otherwise healthy individuals, however some people become fixated on the sensation and its possible meaning, and this fixation may then develop into delusional parasitosis.
). Sufferers may injure themselves in attempts to be rid of the "parasites". Some are able to induce the condition in others through suggestion
, in which case the term folie à deux
may be applicable.
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 sufferers commonly compulsively gather such "evidence" and then present it to medical professionals when seeking help. This presenting of "evidence" is known as "the matchbox sign" because the "evidence" is frequently presented in a small container, such as a matchbox.
Delusional parasitosis is seen more commonly in women, and the frequency is much higher past the age of 40.
The peer reviewed Dermatology Online Journal
has recently noted a very rare form of delusional parasitosis called delusional tinea
.
s and schizophrenia
. In the past, pimozide
was the drug of choice when selecting from the typical antipsychotic
s. Currently, atypical antipsychotic
s such as olanzapine
or risperidone
are used as first line treatment.
However, it is also characteristic that sufferers will reject the diagnosis of delusional parasitosis by medical professionals, and very few are willing to be treated, despite demonstrable efficacy of treatment.
, rather than on or in their body.
" was introduced in 2004 to describe a skin condition characterized by a range of cutaneous (skin) symptoms including crawling, biting, and stinging sensations; finding fibers on or under the skin; and persistent skin lesions (e.g., rashes or sores). A majority of health professionals, including most dermatologists, regard Morgellons as a manifestation of other known medical conditions, including delusional parasitosis and believe any fibers found are from textiles such as clothing. The Morgellons Research Foundation, a non-profit advocacy organization, believes that it is a new infectious disease that will be confirmed by future research. "Other health professionals don't acknowledge Morgellons disease or are reserving judgment until more is known about the condition." Research into the proposed condition is ongoing.
The Philip K. Dick novel A Scanner Darkly
contains a character named Jerry Fabin who suffers from intense Delusional Parasitosis.
The movie Bug (2006 film)
is about a couple who experience Delusional parasitosis together.
In Scott Sigler
's novels Infected and Contagious, skin infestations by alien parasites are discounted as Delusional parasitosis
, specifically Morgellons
.
Psychosis
Psychosis means abnormal condition of the mind, and is a generic psychiatric term for a mental state often described as involving a "loss of contact with reality"...
whose victims acquire a strong delusion
Delusion
A delusion is a false belief held with absolute conviction despite superior evidence. Unlike hallucinations, delusions are always pathological...
al belief that they are infested with parasites, whereas in reality no such parasites are present. Very often the imaginary parasites are reported as being "bugs" or insects crawling on or under the skin; in these cases the experience of the sensation known as formication
Formication
Formication is the medical term for a sensation that resembles that of insects crawling on the skin. It is one specific form of a set of sensations known as paresthesia, which also include the more common prickling, tingling sensation of "pins and needles"...
may provide the basis for this belief.
Delusional parasitosis is also sometimes referred to as "Ekbom's syndrome", named after a Swedish neurologist, Karl Axel Ekbom, who published seminal accounts of the disease in 1937 and 1938. But this name can be confusing because others use the term Ekbom's syndrome interchangeably with Wittmaack-Ekbom syndrome, another name for restless legs syndrome
Restless legs syndrome
Restless legs syndrome or Willis-Ekbom disease is a neurological disorder characterized by an irresistible urge to move one's body to stop uncomfortable or odd sensations. It most commonly affects the legs, but can affect the arms, torso, and even phantom limbs...
(RLS). Although delusional parasitosis and RLS were both researched by Ekbom, and RLS sufferers sometimes describe some of their symptoms as if they have, for example, "ants in my veins", the similarities stop there. RLS is a physical condition with physical causes, whereas delusional parasitosis is a false belief.
The false belief of delusional parasitosis stands in contrast to actual cases of parasitosis, such as scabies
Scabies
Scabies , known colloquially as the seven-year itch, is a contagious skin infection that occurs among humans and other animals. It is caused by a tiny and usually not directly visible parasite, the mite Sarcoptes scabiei, which burrows under the host's skin, causing intense allergic itching...
.
People with delusional parasitosis are likely to ask for help not from psychiatrists but from dermatologists, veterinarian
Veterinarian
A veterinary physician, colloquially called a vet, shortened from veterinarian or veterinary surgeon , is a professional who treats disease, disorder and injury in animals....
s, pest control
Pest control
Pest control refers to the regulation or management of a species defined as a pest, usually because it is perceived to be detrimental to a person's health, the ecology or the economy.-History:...
specialists, or entomologists. Because delusional parasitosis is not at all well known to non-specialists, under those circumstances the condition often goes undiagnosed, or may be incorrectly diagnosed.
Classification
Delusional parasitosis is divided into primary, secondary functional and secondary organic groups.Primary
In primary delusional parasitosis, the delusions comprise the entire disease entity, there is no additional deterioration of basic mental functioning or idiosyncratic thought processes. The parasitic delusions consist of a single delusional belief regarding some aspect of health. This is also referred to as "monosymptomatic hypochondriacal psychosis", and sometimes as "true" delusional parasitosis. In the DSM-IV, this corresponds with "delusional disorder, somatic type".Secondary functional
Secondary functional delusional parasitosis occurs when the delusions are associated with a psychiatric condition such as schizophreniaSchizophrenia
Schizophrenia is a mental disorder characterized by a disintegration of thought processes and of emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social...
or clinical depression
Clinical depression
Major depressive disorder is a mental disorder characterized by an all-encompassing low mood accompanied by low self-esteem, and by loss of interest or pleasure in normally enjoyable activities...
.
Secondary organic
Secondary organic delusional parasitosis occurs when the state of the patient is caused by a medical illness or substance (medical or recreational) use. In the DSM-IV this corresponds with "psychotic disorder due to general medical condition". Physical illnesses that can underlie secondary organic delusional parasitosis include: hypothyroidismHypothyroidism
Hypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone.Iodine deficiency is the most common cause of hypothyroidism worldwide but it can be caused by other causes such as several conditions of the thyroid gland or, less commonly, the pituitary gland or...
, cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
, cerebrovascular disease
Cerebrovascular disease
Cerebrovascular disease is a group of brain dysfunctions related to disease of the blood vessels supplying the brain. Hypertension is the most important cause; it damages the blood vessel lining, endothelium, exposing the underlying collagen where platelets aggregate to initiate a repairing process...
, tuberculosis
Tuberculosis
Tuberculosis, MTB, or TB is a common, and in many cases lethal, infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis. Tuberculosis usually attacks the lungs but can also affect other parts of the body...
, neurological disorders, vitamin B12 deficiency
Vitamin B12 deficiency
Vitamin B12 deficiency or hypocobalaminemia is a low blood level of vitamin B12, it can cause permanent damage to nervous tissue as a long term effect. Vitamin B12 was discovered from its relationship to the disease pernicious anemia, which is an autoimmune disease that destroys parietal cells in...
, and diabetes mellitus
Diabetes mellitus
Diabetes mellitus, often simply referred to as diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced...
. Any illness or medication for which formication
Formication
Formication is the medical term for a sensation that resembles that of insects crawling on the skin. It is one specific form of a set of sensations known as paresthesia, which also include the more common prickling, tingling sensation of "pins and needles"...
is a symptom or side effect can become a trigger or underlying cause of delusional parasitosis.
Other physiological factors which can cause formication and thus can sometimes lead to this condition include: menopause
Menopause
Menopause is a term used to describe the permanent cessation of the primary functions of the human ovaries: the ripening and release of ova and the release of hormones that cause both the creation of the uterine lining and the subsequent shedding of the uterine lining...
(i.e. hormone withdrawal); allergies, and drug abuse, including but not limited to cocaine
Cocaine
Cocaine is a crystalline tropane alkaloid that is obtained from the leaves of the coca plant. The name comes from "coca" in addition to the alkaloid suffix -ine, forming cocaine. It is a stimulant of the central nervous system, an appetite suppressant, and a topical anesthetic...
and methamphetamine
Methamphetamine
Methamphetamine is a psychostimulant of the phenethylamine and amphetamine class of psychoactive drugs...
(as in amphetamine psychosis
Amphetamine psychosis
Stimulant psychosis is a psychotic disorder that appears in some people who use stimulant drugs. Most commonly, stimulant psychosis occurs in drug abusers who take very large doses but, in rare cases, it can also present in patients taking therapeutic doses under medical supervision...
). It appears that many of these physiological factors, as well as environmental factors such as airborne irritants, are capable of inducing a "crawling" sensation in otherwise healthy individuals, however some people become fixated on the sensation and its possible meaning, and this fixation may then develop into delusional parasitosis.
Presentation
Details of delusional parasitosis vary among sufferers, but is most commonly described as involving perceived parasites crawling upon or burrowing into the skin, sometimes accompanied by an actual physical sensation (known as formicationFormication
Formication is the medical term for a sensation that resembles that of insects crawling on the skin. It is one specific form of a set of sensations known as paresthesia, which also include the more common prickling, tingling sensation of "pins and needles"...
). Sufferers may injure themselves in attempts to be rid of the "parasites". Some are able to induce the condition in others through suggestion
Suggestion
Suggestion is the psychological process by which one person guides the thoughts, feelings, or behaviour of another. Nineteenth century writers on psychology such as William James used the words "suggest" and "suggestion" in senses close to those they have in common speech—one idea was said to...
, in which case the term folie à deux
Folie à deux
-Further reading:*Halgin, R. & Whitbourne, S. Abnormal Psychology: Clinical Perspectives on Psychological Disorders. McGraw-Hill. ISBN 0072817216...
may be applicable.
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 sufferers commonly compulsively gather such "evidence" and then present it to medical professionals when seeking help. This presenting of "evidence" is known as "the matchbox sign" because the "evidence" is frequently presented in a small container, such as a matchbox.
Delusional parasitosis is seen more commonly in women, and the frequency is much higher past the age of 40.
The peer reviewed Dermatology Online Journal
Dermatology Online Journal
The Dermatology Online Journal is a monthly open-access peer-reviewed medical journal that was established in 1995 by Arthur Huntley . It is published by the California Digital Library and covers all aspects of general dermatology. The journal is indexed and abstracted in MEDLINE...
has recently noted a very rare form of delusional parasitosis called delusional tinea
Tinea
Tinea is a general term used to describe skin mycoses. The term ringworm is even less precise, but is usually considered a synonym.It is sometimes equated with dermatophytosis, and it is true that most conditions identified as "tinea" are members of the imperfect fungi that make up the dermatophytes...
.
Treatment
Treatment of secondary forms of delusional parasitosis are addressed by treating the primary associated psychological or physical condition. The primary form is treated much as other delusional disorderDelusional disorder
Delusional disorder is an uncommon psychiatric condition in which patients present with circumscribed symptoms of non-bizarre delusions, but with the absence of prominent hallucinations and no thought disorder, mood disorder, or significant flattening of affect...
s and schizophrenia
Schizophrenia
Schizophrenia is a mental disorder characterized by a disintegration of thought processes and of emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social...
. In the past, pimozide
Pimozide
Pimozide is an antipsychotic drug of the diphenylbutylpiperidine class. It was discovered at Janssen Pharmaceutica in 1963. It has a high potency compared to chlorpromazine . On a weight basis it is even more potent than haloperidol. It also has special neurologic indications for Tourette syndrome...
was the drug of choice when selecting from the typical antipsychotic
Typical antipsychotic
Typical antipsychotics are a class of antipsychotic drugs first developed in the 1950s and used to treat psychosis...
s. Currently, atypical antipsychotic
Atypical antipsychotic
The atypical antipsychotics are a group of antipsychotic tranquilizing drugs used to treat psychiatric conditions. Some atypical antipsychotics are FDA approved for use in the treatment of schizophrenia...
s such as olanzapine
Olanzapine
Olanzapine is an atypical antipsychotic, approved by the FDA for the treatment of schizophrenia and bipolar disorder...
or risperidone
Risperidone
Risperidone is a second generation or atypical antipsychotic, sold under the trade name . It is used to treat schizophrenia , schizoaffective disorder, the mixed and manic states associated with bipolar disorder, and irritability in people with autism...
are used as first line treatment.
However, it is also characteristic that sufferers will reject the diagnosis of delusional parasitosis by medical professionals, and very few are willing to be treated, despite demonstrable efficacy of treatment.
Delusory cleptoparasitosis
Delusory cleptoparasitosis is a form of delusion of parasitosis where the sufferer believes the infestation is in their dwellingDwelling
Dwelling, as well as being a term for a house, or for living somewhere, or for lingering somewhere, is a philosophical concept which was developed by Martin Heidegger. Dwelling is about making yourself at home where the home itself is a building that is a house...
, rather than on or in their body.
Morgellons
The term "MorgellonsMorgellons
Morgellons , is a name given in 2002 by Mary Leitao to a proposed condition characterized by a range of cutaneous symptoms including crawling, biting, and stinging sensations ; finding fibers on or under the skin; and persistent skin lesions...
" was introduced in 2004 to describe a skin condition characterized by a range of cutaneous (skin) symptoms including crawling, biting, and stinging sensations; finding fibers on or under the skin; and persistent skin lesions (e.g., rashes or sores). A majority of health professionals, including most dermatologists, regard Morgellons as a manifestation of other known medical conditions, including delusional parasitosis and believe any fibers found are from textiles such as clothing. The Morgellons Research Foundation, a non-profit advocacy organization, believes that it is a new infectious disease that will be confirmed by future research. "Other health professionals don't acknowledge Morgellons disease or are reserving judgment until more is known about the condition." Research into the proposed condition is ongoing.
In Popular Culture
In season 5 episode 7 of the television show House Dr.Wilson diagnoses Dr.House as having Delusional Parasitosis.The Philip K. Dick novel A Scanner Darkly
A Scanner Darkly
A Scanner Darkly is a BSFA Award winning 1977 science fiction novel by American writer Philip K. Dick. The semi-autobiographical story is set in a dystopian Orange County, California, in the then-future of June 1994...
contains a character named Jerry Fabin who suffers from intense Delusional Parasitosis.
The movie Bug (2006 film)
Bug (2006 film)
Bug is a 2006 American horror/thriller directed by William Friedkin, and starring Ashley Judd, Michael Shannon and Harry Connick, Jr..The film is based on the play of the same name written by Tracy Letts.-Plot:...
is about a couple who experience Delusional parasitosis together.
In Scott Sigler
Scott Sigler
Scott Carl Sigler is a contemporary American author of science fiction and horror as well as an avid podcaster. Originally from Michigan he now resides in San Francisco, California with his wife and their dog, Emma.-Biography:...
's novels Infected and Contagious, skin infestations by alien parasites are discounted as Delusional parasitosis
Delusional parasitosis
Delusional parasitosis is a form of psychosis whose victims acquire a strong delusional belief that they are infested with parasites, whereas in reality no such parasites are present...
, specifically Morgellons
Morgellons
Morgellons , is a name given in 2002 by Mary Leitao to a proposed condition characterized by a range of cutaneous symptoms including crawling, biting, and stinging sensations ; finding fibers on or under the skin; and persistent skin lesions...
.
Further reading
- Berrios, G E (1985). Delusional Parasitosis and Physical Disease. Comprehensive Psychiatry 26(5):395-403.
- Frances, A and Munro, A (1989). Treating a woman who believes she has bugs under her skin. Hospital and Community Psychiatry 40(11):1113-1114.
External links
- The Bohart Museum of Entomology; Human Skin Parasites & Delusional Parasitosis
- Psychogenic Parasitosis Slaughter, James R., et al., Psychosomatics 39:491-500, December 1998
- medical dictionary definitions of Ekbom's syndrome