- Email: [email protected]
Delusions of ocular parasitosis
Delusions of Ocular Parasitosis MARK D. SHERMAN, MD, GARY N. HOLLAND, MD, DOUGLAS S. HOLSCLAW, MD, JAMES M. WEISZ, MD, OSAMA H. M. OMAR, MD, AND RONALD A. SHERMAN, MD
● PURPOSE: To describe four cases of delusions of parasitosis in which self-inflicted ocular trauma occurred. Delusions of parasitosis is a somatic delusional disorder in which patients have the irrational belief that their bodies are infested by parasites or other infectious organisms. Self-inflicted trauma can result from attempts to eliminate the supposed infestation. ● METHODS: We reviewed the case histories of four patients (one male, three females, 35 to 45 years of age) who presented with complaints of ocular infestation but had no evidence of infectious ocular disease. The characteristics of these cases were compared with the features of delusions of parasitosis. ● RESULTS: All patients maintained their beliefs regarding infestation, despite extensive clinical and laboratory investigations that found no evidence of infectious diseases. Self-inflicted eye injury, associated with attempts to eliminate the infestation, occurred in each case. ● CONCLUSIONS: The cases presented in this report are consistent with a diagnosis of delusions of parasitosis. The eye can be a principal focus of attention in this disorder, which may lead to vision loss caused by self-inflicted injury. (Am J Oph-
Accepted for publication Oct 22, 1997. From the Southern California Permanente Medical Group, Cornea/ External Disease Service (Dr Sherman) and UCLA Ocular Inflammatory Disease Center, The Jules Stein Eye Institute, and Department of Ophthalmology, UCLA School of Medicine, and Ophthalmology Section, Surgical Service, West Los Angeles Department of Veterans Affairs Medical Center (Drs Holland, Weisz, and Omar), Los Angeles, California; University of California, San Francisco, School of Medicine, Department of Ophthalmology and The Francis I. Proctor Foundation, San Francisco, California (Dr Holsclaw); and University of California, Irvine, School of Medicine, Division of Infectious Disease, Department of Medicine, Irvine, California (Dr Sherman). Reprint requests to Mark D. Sherman, MD, Department of Ophthalmology, 411 N Lakeview Ave, Anaheim, CA 92807-3028; fax: (714) 279-6204; e-mail: [email protected]
852
©
1998 BY
thalmol 1998;125:852– 856. © 1998 by Elsevier Science Inc. All rights reserved.)
D
ELUSIONS OF PARASITOSIS IS DEFINED AS AN
erroneous but unshakable belief that the body is infested by parasites or other infectious organisms.1–3 It is a well-characterized disorder seen most commonly by dermatologists and infectious disease specialists.4 –7 Delusions of parasitosis has been described as “the most difficult problem of management in dermatology.”1 We present four patients with delusions of parasitosis in which the principal focus of attention was their eyes.
CASE REPORTS ● CASE 1:
A 40-year-old woman presented to the emergency room for evaluation of periorbital erythema. She reported that her home was infested with insects and that her eyes were infested as well. She demonstrated how she would remove the insect particles from her eyes with a cotton-tip swab. There was no known history of psychiatric disorders. There was no history of recent substance abuse. Visual acuity (contact lens correction in the right eye only) was RE, 20/30 and LE, counting fingers. Intraocular pressure was normal in both eyes. External examination demonstrated moderate left eyelid erythema. The left bulbar conjunctiva had marked chemosis and the left cornea demonstrated punctate epithelial keratopathy. There were no other signs of local or systemic infestation. Eyelid cultures demonstrated rare colonies of coagulasenegative Staphylococcus species. The patient was treated with topical erythromycin ointment and follow-up at the outpatient ophthalmology clinic was arranged. An emergency room psychiatry con-
ELSEVIER SCIENCE INC. ALL
RIGHTS RESERVED.
0002-9394/98/$19.00 PII S0002-9394(98)00048-8
sultant determined that she was “not holdable” and arranged an outpatient psychiatric evaluation. She did not keep her follow-up appointments. Six months later, she returned complaining of fungal infestation of both eyes. She described removing material from her left eye with a cotton-tip swab and brought samples of objects she had removed from her eyes, ears, mouth, and rectum. Examination did not reveal a substantial change from her previous emergency room visit. The patient did not return for further follow-up. ● CASE 2:
A 45-year-old woman was seen with a chief complaint of “tiny white worms and yellow tube-bugs shooting out of my skin into my eyes.” She denied any history of ocular, medical, or psychiatric disorders. There was no history of previous substance abuse. The patient had given away one dog and two cats because of her belief that they carried worms. She terminated her friendship with a neighbor, believing the neighbor to be a source of worms. The patient reported a 14-month history of itching, scratching, and a “wiggling sensation” beneath her skin, scalp, eyebrows, and ears. She had been evaluated by more than 10 dermatologists, all of whom she described as being “completely incompetent.” She had been previously referred for psychiatric evaluation but did not keep her appointments. On examination, visual acuity without correction was measured at BE, 20/20. External examination was notable for three discrete patches of alopecia on her scalp. There was mild inspissation of the meibomian glands in the eyelids of both eyes. The tarsal conjunctiva showed a mild papillary reaction in both eyes. The corneas were clear, and the remainder of the anterior and posterior segment examination was unremarkable in both eyes. Eyelid cultures grew coagulase-negative staphylococci. Conjunctival cultures were negative. The patient was treated for blepharitis with eyelid hygiene and preservative-free artificial tears. She returned for follow-up with her eyebrows shaved off, which she explained as an attempt to get rid of the worms. On three subsequent visits, she brought “specimens” which she had removed with her fingernails and taped onto a piece of wax paper. On one occasion, the patient presented with a 3-mm conjunctival
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laceration in the right eye, which she had caused while trying to “dig out worms” with tweezers. ● CASE 3:
A 35-year-old home health care nurse was seen with a nonresolving corneal ulcer in her left eye. She had been using an assortment of prescribed, as well as over-the-counter, topical medications. Her ocular, medical, and family histories were unremarkable. There was no known history of psychiatric disorders. The patient complained that “little crawlies” had infested her left eye. On examination, her visual acuity without spectacle correction was RE, 20/20 and LE, hand motions. External examination was unremarkable. The right eye was normal. On the left, there was a mild papillary reaction of the lower tarsal conjunctiva. The cornea showed a dense midstromal focal infiltrate in the upper nasal quadrant and multiple small satellite infiltrates in the midperiphery. A 6-mm epithelial defect was present. The anterior chamber was quiet and posterior pole was normal. Cultures were obtained and she was started on topical fortified antibiotics. The cultures showed no growth and smears showed inflammatory cells but no organisms. There was no other sign of local or systemic infestation. After 2 weeks without improvement, a corneal biopsy was performed and demonstrated Candida albicans. She was started on topical amphotericin B 0.15% every hour and oral ketoconazole (200 mg twice a day). The cornea became progressively necrotic and a therapeutic penetrating keratoplasty was performed. The patient did well for 6 weeks, obtaining 20/80 vision in that eye. Despite a successful graft, she was not convinced that the infection had been eradicated. Eight weeks after surgery, she presented to the office complaining of bugs crawling out of her eye, nostrils, and rectum. She said they were on her furniture, in her cat’s eye, and was concerned that her children may carry them as well. As evidence, she brought a culturette with which she cultured her cat’s eye and collected “specimens” that she taped to a sheet of paper. On examination, she was found to have a dense corneal infiltrate that involved the donor cornea as well as the recipient bed and sclera. She underwent urgent limbus-to-limbus penetrating keratoplasty. Cultures obtained in the office and intraoperatively grew Lactobacillus species. Her postoperative course was OCULAR PARASITOSIS
853
complicated by repeated episodes of epithelial breakdown that healed with patching. Ultimately the graft failed and a conjunctival flap was performed. She was treated during this period with fluoxetine (Prozac) on the recommendation of the inpatient psychiatry consultant, who felt she suffered from an obsessive-compulsive disorder. She was referred for continued outpatient psychiatry care but did not keep her appointments because she felt that hers was not a psychiatric disorder. Once the conjunctival flap was performed, the patient was convinced that the infestation was gone and she has done well, despite her decreased vision.
included three women and one man. The average age was 40 years (range, 35 to 45 years). Each patient maintained the belief that his or her eyes were infested despite exhaustive clinical and laboratory evidence to the contrary. Three patients submitted “specimens” of their supposed infectious agents. Patients attributed their conditions to a variety of organisms, including fungi (Case 1), worms (Case 2), parasites (Case 3), and lice (Case 4). Three patients presented to the ophthalmologist with a complaint of concomitant nonocular infestation. One patient, who initially presented with an isolated ocular complaint, later developed systemic complaints. Three patients underwent at least an initial psychiatric evaluation. One of these patients was diagnosed with bipolar affective disorder, and another was diagnosed with obsessive-compulsive disorder. None of the patients continued with their formal psychiatric evaluation. Self-inflicted eye injury occurred in each case. Three patients sustained bilateral ocular injury, and the other had unilateral injury. Injuries were mechanical in two patients, chemical in one patient, and combined chemical and mechanical in one patient. Visual acuity ranged from 20/20 to hand motions in the involved eyes. The spectrum of tissue damage included periocular excoriation, papillary conjunctivitis and chemosis, conjunctival laceration, corneal epithelial toxicity, and corneal stromal ulceration. One patient required surgical intervention.
● CASE 4:
A 40-year-old man presented to the emergency room complaining of 3 weeks of severe burning, tearing, and light sensitivity of both eyes. The patient reported that he was “infested with lice” and had been bathing in, and applying to both eyes, antilice medication. He was homeless. There was no history of recent substance abuse. Visual acuity without correction was BE, counting fingers at 10 feet. External examination revealed multiple periocular superficial excoriations. The eyelids were moderately erythematous. The bulbar conjunctiva was injected and mildly chemotic bilaterally. No signs of lice were visible in the periocular region or along the eyelids. Both corneas had epithelial defects involving over 90% of the corneal surface, moderate stromal haze, and mild edema without infiltrate. He was treated with erythromycin ointment and unilateral patching, which the patient promptly removed in order to “get at the lice.” Dermatologic evaluation revealed no objective signs of local or systemic parasitic infection. Psychiatric consultation resulted in a diagnosis of bipolar disorder, and the patient was admitted for inpatient psychiatric stabilization. The patient was followed for approximately 13 days, during which time there was no re-epithelialization of the corneas, and he persistently claimed his eyes were infested with lice. After 2 weeks of hospitalization, the patient left the hospital against medical advice and was lost to follow-up.
DISCUSSION DELUSIONS OF PARASITOSIS WAS FIRST DESCRIBED BY
the French dermatologist Thibierge in 1894.8 Before 1946, the condition was known by a variety of names, including acarophobia, dermatophobia, and parasitophobia. Wilson and Miller coined the name “delusions of parasitosis” to distinguish the unshakable conviction that the skin is infested from the fear of infestation.9,10 Patients with delusions of parasitosis characteristically come to the physician complaining of itching, biting, and crawling sensations. They may point to “tracks” on their skin and describe the “life-cycle” of the parasite. Frequently they have had multiple encounters with physicians
RESULTS FOUR CASES OF DELUSIONS OF PARASITOSIS WITH
ocular involvement are described. The patients 854
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OPHTHALMOLOGY
JUNE 1998
and may describe with hostility the ineptitude of the physicians at recognizing or curing the disease.6 The patients may report multiple changes in domicile, extensive use of pesticides at home, and even elimination of family pets thought to be possible intermediate hosts for the parasites.4,6,7 Consultation with a psychiatrist is unusual because the patients are not easily convinced that psychiatric evaluation is indicated and they are resistant to thorough psychiatric evaluation.11–13 The most extensive survey of patients with delusions of parasitosis was reported by Lyell.1 In his series of cases, he found a 1:1 male to female ratio for patients under 50 years of age and 3:1 ratio for patients over 50 years of age. Lyell described patients with a variety of personality types, including those with paranoid and aggressive personalities. Two theories have been proposed to explain the behavior manifested in patients with delusions of parasitosis.6,14 –17 The first theory suggests that the major problem is a primary somatic delusional state known as formication, in which the patient displays monosymptomatic hypochondriacal psychosis. The second theory suggests that the delusion is an elaboration of another pathologic state, such as tactile hallucinations, pruritus, or paresthesias. Patients may remain functional in other areas of their lives.6 The skin lesions manifested in patients with delusions of parasitosis can be classified into the following categories: psychosomatic dermatoses (neurodermatitis); physical trauma resulting from attempts to remove the “parasites” with fingernails or other instruments; and chemical trauma caused by solvents and soaps used to kill or remove the “parasites.” In some cases, however, no abnormality of the skin may be discernible. Patients frequently bring “samples” of the parasites wrapped in tissue, enclosed in small containers (the “matchbox sign”), or sealed in envelopes.1,3 Careful examination of these specimens is imperative. In cases of delusions of parasitosis, these specimens generally turn out to be bits of dirt, mucus, or keratotic skin debris. The differential diagnosis of self-inflicted skin injury includes factitial dermatitis, Munchausen syndrome, neurotic excoriation, trichotillomania, and various organic disorders.18 Factitial dermatitis is a condition in which patients produce skin lesions VOL. 125, NO. 6
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through their own purposeful actions, in order to draw attention to themselves. They generally deny any role in the production of these lesions. Munchausen syndrome refers to patients that repeatedly feign disease to obtain secondary gain. These patients typically appear in emergency departments demanding pain relief and, when confronted with the suspicion of self-induced disease, leave and seek their desired care elsewhere. Patients with neurotic excoriation readily admit to manipulation of the skin in order to reduce an uncontrollable urge to scratch or pick at the area involved. Trichotillomania refers to repetitive plucking of hair from the eyebrows, eyelashes, scalp, and body. Delusions of parasitosis has been described in patients with various organic disorders, including vitamin B12 deficiency, renal failure, Hodgkin disease, hypothyroidism, diabetes mellitus, and hepatobiliary dysfunction.6,9,19 It has also been reported in association with alcohol, cocaine, amphetamine, and certain monoamine oxidase inhibitor use.1,6,13 Ophthalmologists considering the diagnosis of delusions of parasitosis must rule out the possibility of any unusual ocular infection and exclude the possibility of organic disease.3,6,11,20 Various treatments for delusions of parasitosis have been described.11,21 Psychotherapy has a reported efficacy rate close to the spontaneous cure rate.6,9,15,22 Nonpharmacologic treatments, such as electroconvulsive therapy and frontal lobotomy, have also been tried without notable success.2 Pharmacologic treatment has included neuroleptics, placebo medications, benzodiazepines, and monoamine oxidase inhibitors.6,17 Pimozide, a neuroleptic drug, has shown some benefit.21,23 Unfortunately, pimozide is associated with substantial adverse side effects, and its dose must be carefully titrated. We have described four cases of delusions of parasitosis in which a principal focus of attention was the eyes. Epidemiologic studies have shown that the prevalence of delusions of parasitosis is far greater than suggested by the medical literature.3 This condition is probably more common in the general ophthalmology practice than currently recognized as well. We refer to this variant of the condition as “delusions of ocular parasitosis” to accentuate sight-threatening features, as seen in our patients, from the more typical syndrome. We hope OCULAR PARASITOSIS
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10. Wilson JW. Delusions of parasitosis (acarophobia): further observations in clinical practice. Arch Dermatol Syphilol 1952;66:577–585. 11. Gould WM, Gragg TM. Delusions of parasitosis: an approach to the problem. Arch Dermatol 1976;112:1745– 1748. 12. Munro A. Delusions of parasitosis [letter]. Br Med J 1977;1:1219. 13. Tullett GL. Delusions of parasitosis. Br J Derm 1965;77: 448 – 454. 14. Munro A. Monosymptomatic hypochondriacal psychosis manifesting as delusions of parasitosis. Arch Dermatol 1978;114:940 –943. 15. Kushon DJ, Helz JW, Williams JM, et al. Delusions of parasitosis: a survey of entomologists from a psychiatric perspective. Bulletin of the Society for Vector Ecology 1993;18:11–15. 16. Berrios GE. Delusions of parasitosis and physical disease. Compr Psychiatry 1985;26:395– 403. 17. Monk BE, Rao YJ. Delusions of parasitosis with fatal outcome. Clin Exp Dermatol 1994;19:341–342. 18. Fabisch, W. Psychiatric aspects of dermatitis artefacta. Br J Derm 1980;102:29 –34. 19. Pope FM. Parasitophobia as the presenting symptom of vitamin B12 deficiency. Practitioner 1970;204:421– 459. 20. Soylu M, Ozcan K, Yalaz M, et al. Dirofilariasis: an uncommon parasitosis of the eye. Br J Ophthalmol 1993; 77:602– 603. 21. Reilly TM, Jopling WH, Beard AW. Successful treatment with pimozide of delusional parasitosis. Br J Dermatol 1978;98:457– 459. 22. Torch EM, Bishop ER. Delusions of parasitosis: psychotherapeutic engagement. Am J Psychother 1981;35:101–106. 23. Johnson GC, Anton RF. Pimozide in delusions of parasitosis [letter]. J Clin Psychiatry 1983;44:233.
that by drawing the attention of ophthalmologists to this condition, earlier diagnosis and successful treatment will be possible. Earlier consultation with a psychiatrist or psychiatric liaison, emphasizing the risk of vision loss, may improve the possibility of a successful outcome.
REFERENCES 1. Lyell A. Delusions of parasitosis. Br J Dermatol 1983;108: 485– 499. 2. Cotterill JA. Dermatological non-disease: a common and potentially fatal disturbance of cutaneous body image. Br J Dermatol 1981;104:611– 619. 3. Delusions of parasitosis [editorial]. Br Med J 1977;1:790–791. 4. Webb JP. Case histories of individuals with delusions of parasitosis in Southern California and a proposed protocol for initiating effective medical assistance. Bulletin of the Society for Vector Ecology 1993;18:16 –25. 5. Koblenzer CS. The clinical presentation, diagnosis and treatment of delusions of parasitosis: a dermatologic perspective. Bulletin of the Society for Vector Ecology 1993; 18:6 –10. 6. Wykoff RF. Delusions of parasitosis: a review. Rev Inf Dis 1987;9:433– 437. 7. Goddard J. Analysis of 11 cases of delusions of parasitosis reported to the Mississippi Department of Health. South Med J 1995;88:837– 839. 8. Thibierge G. Les acarophobes. Rev Gen Clin Therap 1894;32:373–376. 9. Wilson JW, Miller HE. Delusion of parasitosis. Arch Derm Syphilol 1946;54:39 –56.
Authors Interactivet We encourage questions and comments regarding this article via the Internet on Authors Interactivet at http://www.ajo.com/ Questions, comments, and author responses are posted.
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● PURPOSE: To describe four cases of delusions of parasitosis in which self-inflicted ocular trauma occurred. Delusions of parasitosis is a somatic delusional disorder in which patients have the irrational belief that their bodies are infested by parasites or other infectious organisms. Self-inflicted trauma can result from attempts to eliminate the supposed infestation. ● METHODS: We reviewed the case histories of four patients (one male, three females, 35 to 45 years of age) who presented with complaints of ocular infestation but had no evidence of infectious ocular disease. The characteristics of these cases were compared with the features of delusions of parasitosis. ● RESULTS: All patients maintained their beliefs regarding infestation, despite extensive clinical and laboratory investigations that found no evidence of infectious diseases. Self-inflicted eye injury, associated with attempts to eliminate the infestation, occurred in each case. ● CONCLUSIONS: The cases presented in this report are consistent with a diagnosis of delusions of parasitosis. The eye can be a principal focus of attention in this disorder, which may lead to vision loss caused by self-inflicted injury. (Am J Oph-
Accepted for publication Oct 22, 1997. From the Southern California Permanente Medical Group, Cornea/ External Disease Service (Dr Sherman) and UCLA Ocular Inflammatory Disease Center, The Jules Stein Eye Institute, and Department of Ophthalmology, UCLA School of Medicine, and Ophthalmology Section, Surgical Service, West Los Angeles Department of Veterans Affairs Medical Center (Drs Holland, Weisz, and Omar), Los Angeles, California; University of California, San Francisco, School of Medicine, Department of Ophthalmology and The Francis I. Proctor Foundation, San Francisco, California (Dr Holsclaw); and University of California, Irvine, School of Medicine, Division of Infectious Disease, Department of Medicine, Irvine, California (Dr Sherman). Reprint requests to Mark D. Sherman, MD, Department of Ophthalmology, 411 N Lakeview Ave, Anaheim, CA 92807-3028; fax: (714) 279-6204; e-mail: [email protected]
852
©
1998 BY
thalmol 1998;125:852– 856. © 1998 by Elsevier Science Inc. All rights reserved.)
D
ELUSIONS OF PARASITOSIS IS DEFINED AS AN
erroneous but unshakable belief that the body is infested by parasites or other infectious organisms.1–3 It is a well-characterized disorder seen most commonly by dermatologists and infectious disease specialists.4 –7 Delusions of parasitosis has been described as “the most difficult problem of management in dermatology.”1 We present four patients with delusions of parasitosis in which the principal focus of attention was their eyes.
CASE REPORTS ● CASE 1:
A 40-year-old woman presented to the emergency room for evaluation of periorbital erythema. She reported that her home was infested with insects and that her eyes were infested as well. She demonstrated how she would remove the insect particles from her eyes with a cotton-tip swab. There was no known history of psychiatric disorders. There was no history of recent substance abuse. Visual acuity (contact lens correction in the right eye only) was RE, 20/30 and LE, counting fingers. Intraocular pressure was normal in both eyes. External examination demonstrated moderate left eyelid erythema. The left bulbar conjunctiva had marked chemosis and the left cornea demonstrated punctate epithelial keratopathy. There were no other signs of local or systemic infestation. Eyelid cultures demonstrated rare colonies of coagulasenegative Staphylococcus species. The patient was treated with topical erythromycin ointment and follow-up at the outpatient ophthalmology clinic was arranged. An emergency room psychiatry con-
ELSEVIER SCIENCE INC. ALL
RIGHTS RESERVED.
0002-9394/98/$19.00 PII S0002-9394(98)00048-8
sultant determined that she was “not holdable” and arranged an outpatient psychiatric evaluation. She did not keep her follow-up appointments. Six months later, she returned complaining of fungal infestation of both eyes. She described removing material from her left eye with a cotton-tip swab and brought samples of objects she had removed from her eyes, ears, mouth, and rectum. Examination did not reveal a substantial change from her previous emergency room visit. The patient did not return for further follow-up. ● CASE 2:
A 45-year-old woman was seen with a chief complaint of “tiny white worms and yellow tube-bugs shooting out of my skin into my eyes.” She denied any history of ocular, medical, or psychiatric disorders. There was no history of previous substance abuse. The patient had given away one dog and two cats because of her belief that they carried worms. She terminated her friendship with a neighbor, believing the neighbor to be a source of worms. The patient reported a 14-month history of itching, scratching, and a “wiggling sensation” beneath her skin, scalp, eyebrows, and ears. She had been evaluated by more than 10 dermatologists, all of whom she described as being “completely incompetent.” She had been previously referred for psychiatric evaluation but did not keep her appointments. On examination, visual acuity without correction was measured at BE, 20/20. External examination was notable for three discrete patches of alopecia on her scalp. There was mild inspissation of the meibomian glands in the eyelids of both eyes. The tarsal conjunctiva showed a mild papillary reaction in both eyes. The corneas were clear, and the remainder of the anterior and posterior segment examination was unremarkable in both eyes. Eyelid cultures grew coagulase-negative staphylococci. Conjunctival cultures were negative. The patient was treated for blepharitis with eyelid hygiene and preservative-free artificial tears. She returned for follow-up with her eyebrows shaved off, which she explained as an attempt to get rid of the worms. On three subsequent visits, she brought “specimens” which she had removed with her fingernails and taped onto a piece of wax paper. On one occasion, the patient presented with a 3-mm conjunctival
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OF
laceration in the right eye, which she had caused while trying to “dig out worms” with tweezers. ● CASE 3:
A 35-year-old home health care nurse was seen with a nonresolving corneal ulcer in her left eye. She had been using an assortment of prescribed, as well as over-the-counter, topical medications. Her ocular, medical, and family histories were unremarkable. There was no known history of psychiatric disorders. The patient complained that “little crawlies” had infested her left eye. On examination, her visual acuity without spectacle correction was RE, 20/20 and LE, hand motions. External examination was unremarkable. The right eye was normal. On the left, there was a mild papillary reaction of the lower tarsal conjunctiva. The cornea showed a dense midstromal focal infiltrate in the upper nasal quadrant and multiple small satellite infiltrates in the midperiphery. A 6-mm epithelial defect was present. The anterior chamber was quiet and posterior pole was normal. Cultures were obtained and she was started on topical fortified antibiotics. The cultures showed no growth and smears showed inflammatory cells but no organisms. There was no other sign of local or systemic infestation. After 2 weeks without improvement, a corneal biopsy was performed and demonstrated Candida albicans. She was started on topical amphotericin B 0.15% every hour and oral ketoconazole (200 mg twice a day). The cornea became progressively necrotic and a therapeutic penetrating keratoplasty was performed. The patient did well for 6 weeks, obtaining 20/80 vision in that eye. Despite a successful graft, she was not convinced that the infection had been eradicated. Eight weeks after surgery, she presented to the office complaining of bugs crawling out of her eye, nostrils, and rectum. She said they were on her furniture, in her cat’s eye, and was concerned that her children may carry them as well. As evidence, she brought a culturette with which she cultured her cat’s eye and collected “specimens” that she taped to a sheet of paper. On examination, she was found to have a dense corneal infiltrate that involved the donor cornea as well as the recipient bed and sclera. She underwent urgent limbus-to-limbus penetrating keratoplasty. Cultures obtained in the office and intraoperatively grew Lactobacillus species. Her postoperative course was OCULAR PARASITOSIS
853
complicated by repeated episodes of epithelial breakdown that healed with patching. Ultimately the graft failed and a conjunctival flap was performed. She was treated during this period with fluoxetine (Prozac) on the recommendation of the inpatient psychiatry consultant, who felt she suffered from an obsessive-compulsive disorder. She was referred for continued outpatient psychiatry care but did not keep her appointments because she felt that hers was not a psychiatric disorder. Once the conjunctival flap was performed, the patient was convinced that the infestation was gone and she has done well, despite her decreased vision.
included three women and one man. The average age was 40 years (range, 35 to 45 years). Each patient maintained the belief that his or her eyes were infested despite exhaustive clinical and laboratory evidence to the contrary. Three patients submitted “specimens” of their supposed infectious agents. Patients attributed their conditions to a variety of organisms, including fungi (Case 1), worms (Case 2), parasites (Case 3), and lice (Case 4). Three patients presented to the ophthalmologist with a complaint of concomitant nonocular infestation. One patient, who initially presented with an isolated ocular complaint, later developed systemic complaints. Three patients underwent at least an initial psychiatric evaluation. One of these patients was diagnosed with bipolar affective disorder, and another was diagnosed with obsessive-compulsive disorder. None of the patients continued with their formal psychiatric evaluation. Self-inflicted eye injury occurred in each case. Three patients sustained bilateral ocular injury, and the other had unilateral injury. Injuries were mechanical in two patients, chemical in one patient, and combined chemical and mechanical in one patient. Visual acuity ranged from 20/20 to hand motions in the involved eyes. The spectrum of tissue damage included periocular excoriation, papillary conjunctivitis and chemosis, conjunctival laceration, corneal epithelial toxicity, and corneal stromal ulceration. One patient required surgical intervention.
● CASE 4:
A 40-year-old man presented to the emergency room complaining of 3 weeks of severe burning, tearing, and light sensitivity of both eyes. The patient reported that he was “infested with lice” and had been bathing in, and applying to both eyes, antilice medication. He was homeless. There was no history of recent substance abuse. Visual acuity without correction was BE, counting fingers at 10 feet. External examination revealed multiple periocular superficial excoriations. The eyelids were moderately erythematous. The bulbar conjunctiva was injected and mildly chemotic bilaterally. No signs of lice were visible in the periocular region or along the eyelids. Both corneas had epithelial defects involving over 90% of the corneal surface, moderate stromal haze, and mild edema without infiltrate. He was treated with erythromycin ointment and unilateral patching, which the patient promptly removed in order to “get at the lice.” Dermatologic evaluation revealed no objective signs of local or systemic parasitic infection. Psychiatric consultation resulted in a diagnosis of bipolar disorder, and the patient was admitted for inpatient psychiatric stabilization. The patient was followed for approximately 13 days, during which time there was no re-epithelialization of the corneas, and he persistently claimed his eyes were infested with lice. After 2 weeks of hospitalization, the patient left the hospital against medical advice and was lost to follow-up.
DISCUSSION DELUSIONS OF PARASITOSIS WAS FIRST DESCRIBED BY
the French dermatologist Thibierge in 1894.8 Before 1946, the condition was known by a variety of names, including acarophobia, dermatophobia, and parasitophobia. Wilson and Miller coined the name “delusions of parasitosis” to distinguish the unshakable conviction that the skin is infested from the fear of infestation.9,10 Patients with delusions of parasitosis characteristically come to the physician complaining of itching, biting, and crawling sensations. They may point to “tracks” on their skin and describe the “life-cycle” of the parasite. Frequently they have had multiple encounters with physicians
RESULTS FOUR CASES OF DELUSIONS OF PARASITOSIS WITH
ocular involvement are described. The patients 854
AMERICAN JOURNAL
OF
OPHTHALMOLOGY
JUNE 1998
and may describe with hostility the ineptitude of the physicians at recognizing or curing the disease.6 The patients may report multiple changes in domicile, extensive use of pesticides at home, and even elimination of family pets thought to be possible intermediate hosts for the parasites.4,6,7 Consultation with a psychiatrist is unusual because the patients are not easily convinced that psychiatric evaluation is indicated and they are resistant to thorough psychiatric evaluation.11–13 The most extensive survey of patients with delusions of parasitosis was reported by Lyell.1 In his series of cases, he found a 1:1 male to female ratio for patients under 50 years of age and 3:1 ratio for patients over 50 years of age. Lyell described patients with a variety of personality types, including those with paranoid and aggressive personalities. Two theories have been proposed to explain the behavior manifested in patients with delusions of parasitosis.6,14 –17 The first theory suggests that the major problem is a primary somatic delusional state known as formication, in which the patient displays monosymptomatic hypochondriacal psychosis. The second theory suggests that the delusion is an elaboration of another pathologic state, such as tactile hallucinations, pruritus, or paresthesias. Patients may remain functional in other areas of their lives.6 The skin lesions manifested in patients with delusions of parasitosis can be classified into the following categories: psychosomatic dermatoses (neurodermatitis); physical trauma resulting from attempts to remove the “parasites” with fingernails or other instruments; and chemical trauma caused by solvents and soaps used to kill or remove the “parasites.” In some cases, however, no abnormality of the skin may be discernible. Patients frequently bring “samples” of the parasites wrapped in tissue, enclosed in small containers (the “matchbox sign”), or sealed in envelopes.1,3 Careful examination of these specimens is imperative. In cases of delusions of parasitosis, these specimens generally turn out to be bits of dirt, mucus, or keratotic skin debris. The differential diagnosis of self-inflicted skin injury includes factitial dermatitis, Munchausen syndrome, neurotic excoriation, trichotillomania, and various organic disorders.18 Factitial dermatitis is a condition in which patients produce skin lesions VOL. 125, NO. 6
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through their own purposeful actions, in order to draw attention to themselves. They generally deny any role in the production of these lesions. Munchausen syndrome refers to patients that repeatedly feign disease to obtain secondary gain. These patients typically appear in emergency departments demanding pain relief and, when confronted with the suspicion of self-induced disease, leave and seek their desired care elsewhere. Patients with neurotic excoriation readily admit to manipulation of the skin in order to reduce an uncontrollable urge to scratch or pick at the area involved. Trichotillomania refers to repetitive plucking of hair from the eyebrows, eyelashes, scalp, and body. Delusions of parasitosis has been described in patients with various organic disorders, including vitamin B12 deficiency, renal failure, Hodgkin disease, hypothyroidism, diabetes mellitus, and hepatobiliary dysfunction.6,9,19 It has also been reported in association with alcohol, cocaine, amphetamine, and certain monoamine oxidase inhibitor use.1,6,13 Ophthalmologists considering the diagnosis of delusions of parasitosis must rule out the possibility of any unusual ocular infection and exclude the possibility of organic disease.3,6,11,20 Various treatments for delusions of parasitosis have been described.11,21 Psychotherapy has a reported efficacy rate close to the spontaneous cure rate.6,9,15,22 Nonpharmacologic treatments, such as electroconvulsive therapy and frontal lobotomy, have also been tried without notable success.2 Pharmacologic treatment has included neuroleptics, placebo medications, benzodiazepines, and monoamine oxidase inhibitors.6,17 Pimozide, a neuroleptic drug, has shown some benefit.21,23 Unfortunately, pimozide is associated with substantial adverse side effects, and its dose must be carefully titrated. We have described four cases of delusions of parasitosis in which a principal focus of attention was the eyes. Epidemiologic studies have shown that the prevalence of delusions of parasitosis is far greater than suggested by the medical literature.3 This condition is probably more common in the general ophthalmology practice than currently recognized as well. We refer to this variant of the condition as “delusions of ocular parasitosis” to accentuate sight-threatening features, as seen in our patients, from the more typical syndrome. We hope OCULAR PARASITOSIS
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10. Wilson JW. Delusions of parasitosis (acarophobia): further observations in clinical practice. Arch Dermatol Syphilol 1952;66:577–585. 11. Gould WM, Gragg TM. Delusions of parasitosis: an approach to the problem. Arch Dermatol 1976;112:1745– 1748. 12. Munro A. Delusions of parasitosis [letter]. Br Med J 1977;1:1219. 13. Tullett GL. Delusions of parasitosis. Br J Derm 1965;77: 448 – 454. 14. Munro A. Monosymptomatic hypochondriacal psychosis manifesting as delusions of parasitosis. Arch Dermatol 1978;114:940 –943. 15. Kushon DJ, Helz JW, Williams JM, et al. Delusions of parasitosis: a survey of entomologists from a psychiatric perspective. Bulletin of the Society for Vector Ecology 1993;18:11–15. 16. Berrios GE. Delusions of parasitosis and physical disease. Compr Psychiatry 1985;26:395– 403. 17. Monk BE, Rao YJ. Delusions of parasitosis with fatal outcome. Clin Exp Dermatol 1994;19:341–342. 18. Fabisch, W. Psychiatric aspects of dermatitis artefacta. Br J Derm 1980;102:29 –34. 19. Pope FM. Parasitophobia as the presenting symptom of vitamin B12 deficiency. Practitioner 1970;204:421– 459. 20. Soylu M, Ozcan K, Yalaz M, et al. Dirofilariasis: an uncommon parasitosis of the eye. Br J Ophthalmol 1993; 77:602– 603. 21. Reilly TM, Jopling WH, Beard AW. Successful treatment with pimozide of delusional parasitosis. Br J Dermatol 1978;98:457– 459. 22. Torch EM, Bishop ER. Delusions of parasitosis: psychotherapeutic engagement. Am J Psychother 1981;35:101–106. 23. Johnson GC, Anton RF. Pimozide in delusions of parasitosis [letter]. J Clin Psychiatry 1983;44:233.
that by drawing the attention of ophthalmologists to this condition, earlier diagnosis and successful treatment will be possible. Earlier consultation with a psychiatrist or psychiatric liaison, emphasizing the risk of vision loss, may improve the possibility of a successful outcome.
REFERENCES 1. Lyell A. Delusions of parasitosis. Br J Dermatol 1983;108: 485– 499. 2. Cotterill JA. Dermatological non-disease: a common and potentially fatal disturbance of cutaneous body image. Br J Dermatol 1981;104:611– 619. 3. Delusions of parasitosis [editorial]. Br Med J 1977;1:790–791. 4. Webb JP. Case histories of individuals with delusions of parasitosis in Southern California and a proposed protocol for initiating effective medical assistance. Bulletin of the Society for Vector Ecology 1993;18:16 –25. 5. Koblenzer CS. The clinical presentation, diagnosis and treatment of delusions of parasitosis: a dermatologic perspective. Bulletin of the Society for Vector Ecology 1993; 18:6 –10. 6. Wykoff RF. Delusions of parasitosis: a review. Rev Inf Dis 1987;9:433– 437. 7. Goddard J. Analysis of 11 cases of delusions of parasitosis reported to the Mississippi Department of Health. South Med J 1995;88:837– 839. 8. Thibierge G. Les acarophobes. Rev Gen Clin Therap 1894;32:373–376. 9. Wilson JW, Miller HE. Delusion of parasitosis. Arch Derm Syphilol 1946;54:39 –56.
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AMERICAN JOURNAL
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OPHTHALMOLOGY
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