Collembola Implicated in Delusory Parasitosis

Laurie Barclay, MD

August 02, 2004

Aug. 2, 2004 -- The arthropod Collembola (Springtails) is a common factor in patients originally diagnosed with delusory parasitosis, according to the results of a case-controlled study published in the current (June) issue of the Journal of the New York Entomological Society.

"Delusory a presumed psychiatric condition ascribed to individuals who are convinced, in the absence of any empirical evidence, that they are infected with an insect or parasite," write Deborah Z. Altschuler, from the National Pediculosis Association (NPA), in Needham, Massachusetts, and colleagues. "The symptoms are debilitating and the sufferer's distress is compounded by the lack of a concrete physical diagnosis."

In this single-site clinical study conducted by the NPA and the Oklahoma State Department of Health, multiple skin scrapings from each of 20 individuals diagnosed with delusory parasitosis were examined microscopically. The subjects were part of a larger group of more than 1,500 persons reporting symptoms of stinging, biting, and/or crawling to the NPA, and their symptoms were originally attributed to lice or scabies.

There were more than 300 anomalous findings in skin scrapings from the 20 subjects and none in the controls. These anomalies included pollen, spores, hyphae, mycelium, algae, and what appeared to be insect eggs, larvae, or embryos. Although digital photography of any and all fields of view that appeared incongruous to normal human skin initially revealed no common factor, more extensive examination using imaging software revealed evidence of Collembola in 18 of the 20 subjects.

The authors note that Collembola are abundant in wastewater and contaminated environments with high humidity and abundant organic debris.

"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," the authors write. "Collembola do not need to be human parasites in order to be present in the skin scrapings."

J New York Entomol Soc. 2004;112:87-95

Reviewed by Gary D. Vogin, MD


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