2 6

Delusion of parasitosis is a hypochondrial psychosis,usually monosymptomatic, where the patient is con-vinced of being infested with animal parasites while noobjective evidence exists to support this belief. Thecomplaints are mostly of skin,and rarely of gastrointestinalinfestation.Delusional parasitosis is very real and distressingto the patient, causing him to visit medical centers foradvice from family practitioners, dermatologists, andparasitologists. Most of them however, refuse psychi-atric help. With the persistent and refractory nature ofthe disease, the best that can generally be achieved is forthe patients to shift to a less troublesome chronic phase,during which the delusion partially or even completelyslips into the subconscious, thus allowing for more nor-mal daily functioning.Psychopharmaca such as Pimozidecould be helpful for that kind of conditions.1–3

Shared delusion—folie a deux—is a knownphenomenon in delusional parasitosis.4,5 One or moremembers of the same family often suffer from a mono-symptomatic psychosis, the characteristic delusional statebeing identical. The secondary victims are often familymembers,who are dominated by their spouses, show fil-ial devotion, or are trying to keep family harmony. Theoutbreak may occur at intervals of several months.6 Themoving spirit in most of the cases is the mother.7,8

In this paper we describe a cluster of cases sharedby 5 family members, triggered by a gift, which wasbrought by the daughter from her trip to Nepal, andwhich was believed to be infested with parasites.

Patients

A 25-year-old Israeli woman traveled for 6 monthsto Southeast Asia and brought from Nepal yak-woolsweaters as presents for her family. Soon after her arrivalhome, several members of the family started to complainof being infested by parasites (Table 1). They visitedseveral physicians, and brought them samples from theirhomes, as well as skin and stool samples for examination.All laboratory tests were negative for pathogens.The delu-sional parasitosis, from which each family member suf-fered, is described below.

Mother—Principal CaseA 56-year-old woman, biologist by profession,

attended the Travel Medicine Clinic after having beentreated by at least 20 physicians. She suffered from ageneralized pruritus and her symptoms started about 1week after her daughter returned from a trip to South-east Asia, and brought as presents, yak-wool sweatersfrom Nepal.Believing that the sweaters were infested withfleas, she sealed them in plastic bags and cleaned the housethoroughly several times. She underwent treatment forscabies, and treatment with antihistamines, and went fora vacation overseas. None of these measures provided apermanent relief.She then began to suffer from diarrhea,reduced appetite, and weakness, and as a result was absentfrom work for several days.Direct examination of the skinfor bites, stings, or scabies burrows, and the examinationof dust samples, collected from her immediate sur-roundings, were negative for parasites. Stool sampleswere examined three times for helminthes and protozoaand were also negative. Treatment with metronidazoleand mebendazole did not relieve her suffering.

FatherA 55-year-old man, chemist by profession, felt an

itching and prickling sensation about 4 weeks after hisdaughter’s return. The symptoms began shortly after heopened the bag containing the yak-wool sweaters. Thepruritus was severe enough to cause insomnia. He too,visited many physicians and tried many medications,

BRIEF COMMUNICATION

Travel as a Trigger for Shared Delusional ParasitosisEli Schwartz, Eliezer Witztum, and Kosta Y. Mumcuoglu

Eli Schwartz, MD, DTMH:Travel Medicine Center, MisgavLadach Hospital, Jerusalem; Eliezer Witztum, MD: MentalHealth Center, Beer-Sheva; Kosta Y. Mumcuoglu, PhD:Department of Parasitology, Hebrew University-HadassahMedical School, Jerusalem, Israel.

Reprint requests: Eli Schwartz, MD, DTMH,The Center ofGeographical Medicine, Sheba Medical Center, Tel Hashomer52621, Israel.

J Travel Med 2001; 8:26–28.

including crotamiton, metronidazole, and menbenda-zole, to no avail.

Younger BrotherA 23-year-old unmarried student who was at home

with his parents during the weekends, started to feel itch-iness about 4 weeks after his sister returned from her trip.He described the sensation as a bite followed by itching.The pruritus that appeared on the exposed parts of theskin then spread to his feet,causing muscle pains and trou-bling him when walking.He claimed his body was exud-ing parasites that could be seen on his skin as white spots,or threads. He believed that his intestines were alsoinfested, and that he excreted threadlike parasites evenafter treatment with vermicides.He was treated with lin-dane against scabies, and with antimycotics without reliefof the symptoms.Metronidazole, and antibiotics did nothelp, and antihistamines gave temporary relief. He wasconvinced that he had infected his roommate. Exami-nations of the feces and skin samples, as well as samplescollected from his immediate surroundings were nega-tive for parasites.

GrandmotherA 76-year-old widow (the father’s mother), resided

in another city and was visited by her son periodically.About 3 months after the onset of the symptoms in thefamily, she started complaining of pruritus in her fore-head and scalp, and of loss of hair. She lost weight andsuffered from general feeling of disquiet. She was trou-bled by the possibility of infecting other people andtherefore avoided her family and friends.

CousinA 28-year-old unmarried woman who was living

in a third city, visited only the grandmother, a fewtimes, and complained of the same symptoms as hergrandmother. She did not visit our clinic, and the infor-mation about her “infestation” was given by otherfamily members.

Results

All patients,with the exception of the cousin,wereexamined in our clinic.Three of the patients (the mother,the father, and the younger brother) were living together.The daughter,who brought the yak-wool sweaters fromNepal, and an older brother, who were living in otherparts of the city,were not affected by the delusional par-asitosis. However, the older brother avoided all contactwith other family members for 18 months in order notto become infested. Two patients who were living inentirely different cities visited the 3 patients periodically,however, they had no contact with the traveler or hersweaters.The results of the physical examinations and lab-oratory tests were within normal limits for all patients.The skin and dust samples,which were examined in ourlaboratory, and the stool samples,which were examinedin specialized laboratories,were negative for parasites.Allpatients refused to be treated by a psychiatrist or toreceive psychopharmaca, because they were convincedthat they were infested with parasites.

Their symptoms (see Table 1), i.e., itching,pains, andinsomnia were treated symptomatically.We tried a non-confronting approach by not contradicting the patientwhen he/she described details of the parasite’s behavior,even when we knew that it was not biologically possi-ble,e.g., that the parasites went into their skin and imme-diately came out of it.We also expressed empathy for theirtroubles, showing them that we could understand howdifficult it must be to have such problems. We also triedto gain their confidence and relieve them of the obses-sion that they were a source of contagion. Eighteenmonths after the onset of the delusion, the mother, and3–4 months later the other family members, were prac-tically free of their obsessions.Although since then somerelapses occurred, today all family members are func-tioning normally.

Discussion

The precipitating factor for delusional parasitosis cannot always be identified. However, it has been reportedthat death of a family member, flooding in the patient’shome, injury, and contact with people infested with par-asites were initiating factors.1 In our case the trigger wasyak-wool sweaters brought from Nepal, an endemiccountry for parasitic diseases.Travel as a precipitating fac-tor for delusional parasitosis, either to the traveler or hisrelatives and friends, to the best of our knowledge, hasnot been yet described.

The unusual features in our case are the number (foliea cinq) of people affected and the physical distancebetween them: 2 of the patients lived in entirely differ-

Schwartz e t a l . , Shared Delus ional Paras i tos is 27

Table 1 Major Complaints in a Family with SharedDelusional Parasitosis

Onset of Symptoms†

Family Status* Age Symptoms (weeks)

Mother 56 Skin and intestinal 1Father 55 Skin 4Brother 23 Skin and intestinal 4Grandmother 76 Skin 12Cousin 28 Skin 16

*In relation to the traveler who triggered the symptoms.

†After the return of the traveler from Nepal.

2 8 Journal of Trave l Medic ine , Volume 8, Number 1

ent cities and had no contact with the assumed cause ofinfestation.

The intractability and refractory nature of this dis-order is notable.9–12 Pimozide, an antipsychotic agent, isconsidered the drug of choice.13–15 However, referral forpsychiatric treatment is perceived by the patient as lackof comprehension of their real suffering.

The present case follows the same patterns describedby others:many specialists were consulted,numerous sam-ples were repeatedly taken for analysis from the house,skin and feces, and the house was cleaned thoroughly anumber of times. Perhaps the most significant charac-teristic is the denial that the condition may be psycho-logical and the refusal to take psychiatric drugs.

It must always be kept in mind, that the patient’s dis-tress and suffering are real, causing financial losses dueto absence from work, cleaning costs, and visits to spe-cialists. Symptomatic medication may be prescribed forthe relief of pruritus, pain,or other symptoms. It is moreimportant to treat patients with empathy,providing a placewhere they can express their distress without being stig-matized.16 The patients described here were thus treated,and eventually shifted into a less troublesome phase oftheir disease within 2 years.

With the ever-growing number of people travelingto exotic countries, we anticipate that more patientswith these disorders will attend travel clinics,which spe-cialize in post-travel problems. It is therefore importantto be aware about this unique disorder.

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