Collembola found in
scrapings from individuals diagnosed with delusory parasitosis
07/12/04, Needham, MA - Each year, thousands of Americans complain
to their physicians about itching, stinging, biting and crawling
sensations on or under their skin. Many believe they have head lice
or scabies, though they are often referred to psychiatrists or
prescribed anti-psychotic medications.
Now, a new clinical study indicates that many of these people do
have something in their skin:
Collembola, also known as springtails.
Ninety percent of those who participated in the study were found to
have Collembola, which are ubiquitous in nature and minute in size,
according to the study conducted under the auspices of the National
Pediculosis Association (NPA) in Needham, Mass., and the Oklahoma
State Department of Health.
The findings are reported in the new edition of the Journal of the
New York Entomological Association (full
article, images, video and other information located here), headquartered at the American
Museum of Natural History.
Most of the study participants had been diagnosed with delusory parasitosis, a presumed psychiatric condition among people who
believe they are infested with an insect or parasite.
But the new findings bolster the contention of many patients that
they "actually have something crawling on or under their skin and
are not delusional," said the journal article.
Categorized as hexapods, with six legs, antennas, and no wings,
Collembola feed on algae, fungi, bacteria and decaying matter.
During the past few years, 1,500 people have contacted the NPA to
report the crawling sensations and related symptoms. The study
focused on 20 of these people -- and skin scrapings revealed that
all but two of them had Collembola.
Researchers used special imaging techniques to discover the
Collembola, which are extremely well hidden and easy to miss.
"Collembola as a common denominator in people diagnosed with
delusory parasitosis calls for more research to better understand
the relationship between Collembola and humans and the critical need
to help those who suffer with this condition," said NPA president
Deborah Altschuler, one of six researchers who authored the article.
"We believe the study breaks the century-old logjam that the
sensations of crawling, stinging, and biting are only imagined."
Collembola predominately dwell in soil and litter, preferring wet or
damp surroundings. They sometimes congregate in large numbers under
leaky kitchen or bathroom sinks, swimming pools or in the soil of
Little is known about the health effects of Collembola, or how to
prevent or treat them as a problem for human skin.
The NPA encourages medical professionals, sufferers or anyone with
information on these or similar symptoms to share information by
visiting the NPA's Reporting
Besides Altschuler, authors of the article included Oklahoma State
Health Commissioner Michael Crutcher, Romania-based researchers
Neculai Dulceanu, and Cristina Terinte, Beth Cervantes of NPA and
Louis Sorkin of the American Museum of Natural History in New York.
Press Releases From The NPA
|J. New York Entomol. Soc. 112(1):87–95, 2004
COLLEMBOLA (SPRINGTAILS) (ARTHROPODA: HEXAPODA:
ENTOGNATHA) FOUND IN SCRAPINGS FROM INDIVIDUALS
DIAGNOSED WITH DELUSORY PARASITOSIS
DEBORAH Z. ALTSCHULER,1 MICHAEL CRUTCHER, MD, MPH, FACPM,2
NECULAI DULCEANU, DVM, PHD (DECEASED),3 BETH A. CERVANTES,1
CRISTINA TERINTE, MD, PHD4
AND LOUIS N. SORKIN, BCE5
1National Pediculosis Association, 50 Kearney Road, Needham, Massachusetts 02494;
Commissioner of Health, Oklahoma State Department of Health,
1000 NE 10th Street, Oklahoma City, Oklahoma 73117;
Department of Parasitology, University of Veterinary Medicine, Iasi, Romania;
Department of Pathology, University of Medicine and Pharmacy, Iasi, Romania; and
5Division of Invertebrate Zoology, American Museum of Natural History,
Central Park West at 79th Street, New York, New York 10024-5192
Abstract.—Twenty individuals diagnosed with delusory parasitosis participated in a single site clinical
study under the auspices of the National Pediculosis Association (NPA) and the Oklahoma State
Department of Health. The objective of this study was to determine if there were any common factors in
skin scrapings collected from this population. These individuals, whose symptoms were originally
attributed to lice or scabies, were part of a larger group reporting symptoms of stinging/biting and/or
crawling to the NPA. Multiple skin scrapings from each person were microscopically examined. Any and
all fields of view that appeared incongruous to normal human skin were digitally photographed. When the
photographic images were initially evaluated, no common factor was identified. However, more extensive
scrutiny using imaging software revealed evidence of Collembola in 18 of the 20 participants.
Key words: Collembola, springtail, stinging, biting, crawling, Arthropoda, Hexapoda, Entognatha,
pediculosis, human skin, lice and scabies.
Delusory parasitosis, also known as Ekbom’s Syndrome (Ekbom, 1938), is a presumed
psychiatric condition ascribed to individuals who are convinced, in the absence of any empirical
evidence, that they are infested with an insect or parasite (Novak, 1988; Poorbaugh, 1993;
Webb, 1993a). These individuals experience itching, stinging/biting, and crawling sensations
on or under their skin, which are often associated with excoriations, discoloration, scaling,
tunneling or sores. Their conviction that they are infested is reinforced by their observation
of particles described as sparkly, crusty, crystal-like, white or black specks and/or fibers.
Typically, these individuals have consulted extensively with general physicians, dermatologists,
and entomologists (Kushon et al., 1993) who could not find physical cause for their
complaints. Despite findings ruling out lice, scabies or other medical causes, patients refuse
to accept the diagnosis of delusory parasitosis (Koblenzer, 1993; Webb, 1993b), become
extremely focused on eradicating the pests, and further compromise their skin by frequent
scratching, excessive cleaning, and the application of various remedies such as prescription
pesticides for lice or scabies, household cleaning products, and organic solvents or fuels. The
symptoms are debilitating and the sufferer’s distress is compounded by the lack of a concrete
Vol. 112(1) JOURNAL OF THE NEW YORK ENTOMOLOGICAL SOCIETY 88
Hundreds of sufferers have reported symptoms to the National Pediculosis Association
(NPA), as well as to the Oklahoma State Department of Health, similar to those described
by Traver in reporting her own infestation (Traver, 1951). In response to the compelling
nature of these reports, the NPA agreed to conduct a controlled research study of skin
specimens in cooperation with the Oklahoma State Health Department. Twenty individuals
diagnosed as having delusory parasitosis and ten non-symptomatic controls volunteered to
participate in this effort. The clinical portion of the study was conducted at a single site
during three weeks. Doctors with experience in the skin scraping method of specimen
collection obtained and microscopically examined samples, and all anomalous findings were
photographed. Procedures were instituted to preclude contamination, such as reported by
Study Locale. The clinical portion of this study was conducted at the Oklahoma State
Department of Health, Oklahoma City, Oklahoma between June 28 and July 20, 2000.
Study Participants. Twenty symptomatic participants were selected from the hundreds of
individuals who had previously contacted the NPA regarding an unknown condition possibly
associated with lice and/or scabies but for which these parasites had been ruled out. Their
physicians subsequently diagnosed them as suffering from delusory parasitosis. These
volunteers were accepted on the basis of their willingness to travel to Oklahoma City at their
own expense, complete questionnaires regarding their symptoms and medical history, and
submit to multiple skin scrapings. Ten controls, randomly selected from employees of the
Oklahoma State Health Department, were also enrolled. All participants signed a waiver of
liability and understood that this was an initial research effort.
Intake Evaluations. Intake consisted of having symptomatic participants complete a selfadministered
questionnaire that was similar in content to the ‘‘not-lice’’ survey posted on the
NPA website (www.headlice.org). Body diagrams of ventral and dorsal surfaces were marked
to identify common areas of lesions. Two participants had symptoms without lesions or
dermatitis at the time of the trial.
Specimen Preparation. Trained personnel prepared all skin scrapings. Prior and subsequent
to scraping the skin with a disposable scalpel, symptomatic areas and areas at or around
lesions were cleansed with gauze and alcohol. Immediately after being obtained, the scraped
material was transferred to a fresh microscope slide with a drop of sterile water, coverslipped
and isolated. Between 15 and 35 slides were prepared and examined for each subject.
Scrapings were obtained from non-symptomatic controls from regions of the body where most
lesions were noted on symptomatic participants.
Specimen Photography and Data Tracking. All slides were viewed using an Olympus
BX60 Dual Viewing Microscope. The images that appeared incongruent with normal healthy
skin were photographed using a SPOT RGB digital camera and SPOT software version 3.0.
Each image was assigned a unique identifier and the magnification of the image was recorded.
Images were sized by comparison with images of a B&L micrometer with marks for 0.1 mm
and 0.01 mm that were taken at 1003, 2003 and 4003 magnification with the same camera
and software used in the clinical study. Initial microscopy was non-blinded; i.e., the clinicians
examining and photographing the slides knew that they were from either the study participant
or control group.
89 SPRINGTAILS AND DELUSORY PARASITOSIS (COLLEMBOLA) 2004
Over 300 microscopic fields from study participants who complained of stinging/biting and/
or crawling sensations in their skin appeared incongruent with normal skin and therefore were
photographed for later scrutiny.
Pollen, conidia or spores, hyphae, mycelium or fibers, or what appeared to be clumped skin
or cellular debris were identified during the first six months of image analysis. One or two-cell
algae, nematodes, or what appeared to be insect eggs, larvae or embryos were also identified.
Although everyone in the group had at least one of the above findings, none of the findings
were a common factor in every subject, making it necessary to continue looking for a common
denominator. Because Collembola had been reported from individuals experiencing these
symptoms (Dasgupta and Dasgupta, 1995; Frye, 1997; Scott et al., 1962), they became the
focus of subsequent image analysis.
Identification of Collembola in scrapings from symptomatic study participants required
intensive scrutiny of the photographs and was initially very difficult. Most Collembola were
enmeshed in accumulations of exuviae. Eggs ranged from 20 to 100 microns in diameter. The
size of most Collembola noted was 50–300 microns in length, suggesting a predominance of
nymphs as opposed to adults. To ensure reliability of results, researchers verified at least two
sightings before a subject was considered to have positive Collembola findings. However,
scrapings from 10 of the subjects showed an abundance of Collembola. Evidence of
Collembola was found in images of scrapings from 18 of the 20 individuals that had been
diagnosed as delusional. Of the two participants without lesions or dermatitis at the time of the
trial, one had images positive for Collembola.
Examples of some of these findings and the photographic fields in which they appeared are
provided in Fig. 1–3. Each image was obtained from a different study participant.
Fig. 1: Photomicrograph of debris that demonstrated at higher magnification the presence of
Collembola. Two examples are highlighted and enlarged in Fig. 1a.
Fig. 2: A clearly recognizable Collembola (approximately 100 microns in length) is resting
on top of the debris in the lower right.
Fig. 3: Provides an example of Collembola enmeshed in debris.
Collembola were present in ninety percent of the study participants who complained of
stinging/biting and/or crawling sensations on or under their skin.
Microscopic examination of scrapings of control subjects appeared to be consistent with
normal skin and therefore no photographic images were taken.
More than 1,500 individuals registered with the NPA (data on file) as having stinging/biting
and/or crawling sensations that they initially attributed to lice and/or scabies. Approximately
half of these individuals described three or more abnormalities in skin appearance and
observed two or more different types of skin particles. The demographics and symptoms of
these individuals and the study participants were compared (see Table 1).
The findings of Collembola in images of scrapings from 18 of the 20 symptomatic study
participants supports their contention that they actually have something crawling on or under
their skin and are not delusional. The images were reviewed by entomologists and the
presence of Collembola verified and identified as representative of the families Isotomidae and
Vol. 112(1) JOURNAL OF THE NEW YORK ENTOMOLOGICAL SOCIETY 90
Fig. 1. Debris that demonstrated at higher magnification the presence of Collembola.
91 SPRINGTAILS AND DELUSORY PARASITOSIS (COLLEMBOLA) 2004
Fig. 2. Collembola in debris in lower right.
The study was designed to minimize any possibility of sample contamination in the skin
scrapings. All scrapings were done at a single site by clinicians skilled in the skin scraping
method of collection. Microscopic evaluation of skin scrapings from the ten non-symptomatic
controls showed nothing incongruous with normal skin and were therefore not photographed.
This supports the contention that the methodology employed adequately protected against
sample contamination during collection.
A ‘‘classic’’ report of arthropod infestation was reported by Traver (1951) in which the
author described an infestation by a mite species on her person. Traver (1951) has been
referenced by various authors who gave validity to her infestation. Subsequently, papers were
presented during the Symposium: Delusions of Parasitosis. 18 November 1991 refuting her
findings and attributing them to equipment contamination. The mite was identified by Fain
(1967) as the common house dust mite Dermatophagoides pteronyssus.
The directive to photograph all images associated with abnormal skin was critical to
identifying Collembola in the skin scrapings. The fields contained fungal mycelium, or what
appeared at first glance to be cellular clumps or debris. The Collembola were extremely well
hidden in the exuviae and therefore easy to miss. It was only after intense scrutiny that they
were recognized. In addition, because the Collembola were not always intact or completely in
focus, they were difficult to discern. Given these challenges, it is easy to appreciate why there
have been only a few previous reports of Collembola in human skin.
Vol. 112(1) JOURNAL OF THE NEW YORK ENTOMOLOGICAL SOCIETY 92
Fig. 3. Collembola enmeshed in debris.
Collembola were identified in skin scrapings submitted to the Entomology Branch of the
National Center for Infectious Diseases in 1995 (pers. comm.) by an oncology nurse
diagnosed as having delusory parasitosis. Subsequently, there have been additional reports
that provided evidence of Collembola in skin from one or more individuals diagnosed with
similar symptoms (Dasgupta and Dasgupta, 1995; Frye, 1997). Because the samples were
self-collected and contained a number of other anomalies, including fungi spores and
filaments, foreign fibers, plus an assortment of ‘‘organisms,’’ the finding of Collembola was
regarded as intentional or unintentional sample contamination.
In the current study, in which pains were taken to avoid sample contamination, there were
over 300 anomalous findings in skin scrapings from the 20 symptomatic study participants
and none from controls. These findings included pollen, conidia or spores, hyphae, mycelium,
algae or fibers, clumped skin or cellular debris, an occasional nematode, and what appeared to
be insect eggs, larvae or embryos. These collective anomalies point to the compromised skin
of most of the symptomatic study participants, and could directly or indirectly (through an
immune or allergic response) produce sensations of stinging/biting and/or crawling, as well as
some of the other symptoms.
Collembola are abundant in wastewater and contaminated environments making them of
growing ecotoxicologic importance (Hopkin, 1997). Generally, they feed on decaying matter,
SPRINGTAILS AND DELUSORY PARASITOSIS (COLLEMBOLA) 2004
Table 1. Reporting Registry Data
Participants n ¼ 20
66 or over
between 41 and 65
between 26 and 40
25 or under
General health before onset of symptoms
Others with condition
over the counter
lumps on head, scalp
hair breaking off
eyes watery, itchy
Description of symptoms
one or more of above
Population n ¼ 1681
JOURNAL OF THE NEW YORK ENTOMOLOGICAL SOCIETY 94
Table 1. Continued.
two or more of above
three or more of above
one or more of above
two or more of above
three or more of above
algae, fungi and bacteria. In fact, a fungal infection appears to be a prerequisite condition
before collembolans can gain access into the abdominal cavities of cabbage maggot flies Delia
radicum (Griffiths, 1985). Some species of Collembola are known plant and mushroom pests
and one species has been taken from dried milk powder (Scott, 1996).
Typical collembolan habitats are moist environments with high humidity and abundant
organic debris. These conditions are present in the lesions in symptomatic study participants;
it is possible Collembola found in lesions are opportunistic and that fungal infections
or allergic reactions to pollen, fungi, spores or other organisms may contribute to or be
responsible for the symptoms these individuals experience. Collembola do not need to be
human parasites in order to be present in the skin scrapings.
Photographs were taken of all scrapings showing anything inconsistent with normal skin.
After identifying these anomalies as pollen, spores, etc., more extensive scrutiny revealed
the presence of Collembola. Since it was the pollen, spores, hyphae, fiber and other
microorganisms that prompted the photography, it is not known if Collembola (without any
pollen, spores, etc.) could have been present in the control group.
The population studied in this trial was a subset of over 1,500 individuals registered with
the NPA as experiencing crawling and/or biting/stinging sensations in the absence of lice or
scabies. This general population shares many of the characteristics of those who participated
in the study. Although the questionnaire utilized was self-administered and had its limitations,
it is reasonable to postulate that a percentage of this more general population may very well
have similar findings to the 20 symptomatic individuals who participated in this study.
More research is required before the true prevalence and importance of Collembola in
humans can be ascertained.
The authors would like to acknowledge Ferris J. Barger for his help with microphotography and
Dr. BethAnn Friedman and Jane Cotter for manuscript preparation.
Participants n ¼ 20
Population n ¼ 1681
95 SPRINGTAILS AND DELUSORY PARASITOSIS (COLLEMBOLA) 2004
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