Psychiatry and Clinical Neurosciences

(2003),

57

, 552–553

Blackwell Science, LtdOxford, UKPCNPsychiatric and Clinical Neurosciences1323-13162003 Blackwell Science Pty Ltd575October 2003

1165Sulpiride for delusion of parasitosisT. Takahashi et al.10.1046/j.1323-1316.2003.01165.x

Letter to the Editor552553BEES SGML

Letter to the Editor

Sulpiride for treatment of delusion of parasitosis

Delusion of parasitosis is a form of monosymptomatichypochondriacal psychosis (MHP)

1

that is classified asa somatoform delusional disorder according to

Diag-nostic and Statistical Manual of Mental Disorders

(4thedn; DSM-IV). Individuals with delusion of parasitosishave an intense conviction that small living organs suchas worms or insects infest the skin even though thereis no confirming evidence. This condition is likely tooccur in presenile and senile women.

2

During the pasttwo decades, pimozide has been the first-line treatmentfor delusion of parasitosis and MHP.

1,3,4

Sulpiride,which has a relatively low incidence of extrapyramidaland cardiac symptoms, is often prescribed to the eld-erly. To date only one case report described successfultreatment of delusion of parasitosis with sulpiride.

5

Wereport two patients with delusion of parasitosis whoresponded dramatically to low doses of sulpiride.

Ms A, an 84-year-old woman, was referred toDepartment of Psychiatry at Shinshu UniversitySchool of Medicine by her internist because of thepatient’s intense conviction that many worms werecrawling out of her skin. The patient was under treat-ment for hypertension and diabetes mellitus. At pre-sentation she insisted that tiny worms laid eggseverywhere in the wall, on the floor, and in her clothes,and that numerous worms were attached to her skinand stinging her. Her family reported that this belief ina worm infestation had persisted for 12 months, andthat she cleaned the house and clothes all day long toeradicate the worms. Ms A and her family denied anyprevious history of psychiatric illness. There was noevidence of dementia; on the revised HasegawaDementia Scale she scored 27 of 30, and her IQ esti-mated by the Wechsler Adult Intelligence Scale-Revised block pattern test was 100. Magnetic reso-nance imaging demonstrated signs of multiple smallcerebral infarctions in the basal ganglia and thalamus.

Medication with sulpiride at 50 mg/day improved herdelusion within weeks. She reported that there werefew worms and she could distinguish worms from trash.Her family also reported that she stopped her excessivecleaning. Sulpiride administration was maintained at40 mg/day thereafter, and she remained free fromsymptoms of delusions for approximately 3 years,except for an occasion when she stopped taking sulpir-ide on her own. Her worm delusion reappeared with

discontinuation of sulpiride, then disappeared onresumption of medication.

Mr B, a 71-year-old man, was referred to Depart-ment of Psychiatry at Shinshu University School ofMedicine for persistent delusions of being infested bymany worms. He had undergone hemodialysis twice aweek due to chronic renal failure since the age of55 years. At the age of 70 years he complained of itch-ing of the head and trunk, and had also developed anabnormal sensation of worm bites in his head. He vis-ited the dermatologist, and complained that many liv-ing worms were in his head, and that these worms cameout to sting him. He also brought an amount of scalesand dandruff that were alleged to be worms. Initiallyhe was prescribed an external steroid preparation andoral diazepam at 4 mg/day by the dermatologist but thesymptoms did not improve, and he was then referredto our department. At presentation his memory wasintact and he was fully oriented. He expressed somedispleasure about being referred to a psychiatristbecause he was confident that worms were objectivelypresent and that actual bites were occurring. Medica-tion was started with sulpiride at 50 mg/day and main-tained at 100 mg/day. Improvement occurred withinweeks; the patient reported that the worms had nearlydisappeared and that he felt better. He has rarely com-plained of worms for approximately 2 years, and con-tinues to regularly consult our clinic.

Delusional parasitosis occurs in a wide variety ofillnesses, involving both physical and psychotic disor-ders. In the present two cases delusions of parasitesdeveloped associated with physical conditions, such asdiabetes mellitus and multiple cerebral infarctions inthe first patient, and chronic renal failure in the secondpatient. These conditions are known to be involved inthe development of delusion of parasitosis, due to thepotential of these disorders to alter tactile perception.

6

Since the description by Riding and Munro

4

pimozide has been the first-line treatment for MHPand delusion of parasitosis. However, several casestudies describe successful treatment of MHP withother psychotropic agents (e.g. haloperidol, trifluoper-azine, and tricyclic antidepressants).

7,8

Recently, ris-peridone, a novel atypical antipsychotic agent thatpotently blocks both D2 and 5-HT2 receptors, is alsoeffective in the treatment of MHP.

9,10

De Leon

et al

.discussed the importance of 5-HT2 antagonistic actionsin therapeutic effects on MHP.

10

Sulpirides are highlyselective D2-receptor blockers, and have little 5-HT2antagonistic action. The present report has docu-mented the effectivness of a small dose of sulpiride inthe treatment for MHP. We consider that the D2 block-ade action may play an important role in the therapeu-tic benefit for the present patients. We consider that

Sulpiride for delusion of parasitosis 553

sulpiride may be an another agent for the treatment ofMHP in the elderly.

REFERENCES

1. Munro A. Monosymptomatic hypochondriacal psycho-sis.

Br. J. Psychiatry

1988;

153

(Suppl. 2): 37–40.2. Takahashi T, Tamaru T, Imai J

et al.

Pathology in senilepatients with abnormal body sensation.

Psychogeriatrics

2001;

1

: 139–142.3. Munro A, Mok H. An overview of treatment in para-

noia/delusional disorder.

Can. J. Psychiatry

1995;

40

:616–622.

4. Riding J, Munro A. Pimozide in the treatment of mono-symptomatic hypochondriacal psychosis.

Acta Psychiatr.Scand.

1975;

52

: 23–30.5. Amakusa T. Clinical experiences of sulpiride to cenesto-

pathia.

Seishin Igaku

1974;

16

: 502–503 (in Japanese).6. de Leon J, Antelo RE, Simpson G. Delusion of parasi-

tosis or chronic tactile hallucinosis: Hypothesis abouttheir brain physiopathology.

Compr. Psychiatry

1992;

33

:25–33.

7. Bhatia MS, Jagawat T, Choudhary S. Delusional parasi-tosis: A clinical profile.

Int. J. Psychiatry Med.

2000;

30

:83–91.

8. Morris M. Delusional infestation.

Br. J. Psychiatry

1991;

159

(Suppl. 14): 83–87.9. Freyne A, Kenny E, Cooney C. Delusions of infestation:

A case report of response to risperidone.

Ir. Med. J.

1999;

92

: 435.10. De Leon OA, Furmaga KM, Canterbury AL, Bailey LG.

Risperidone in the treatment of delusions of infestation.

Int. J. Psychiatry Med.

1997;

27

: 403–409.

TOHRU TAKAHASHI,

MD

,HIROSHI OZAWA,

MD

,SHIN INUZUKA,

MD

,YUZURU HARADA,

MD

,

P

h

D

,TOKIJI HANIHARA,

MD

,

P

h

D

,NAOJI AMANO,

MD

,

P

h

D

Department of Psychiatry, Shinshu UniversitySchool of Medicine, Matsumoto, Japan

t-tohru@hsp.md.shinshu-u.ac.jp

Correspondence address: Dr Tohru Takahashi, Department of Psy-chiatry, Shinshu University School of Medicine, Asahimachi 3-1-1,Matsumoto 390-8621, Japan. Email: t-tohru@hsp.md.shinshu-u.ac.jp

Received 3 February 2003; revised 31 March 2003; accepted 6April 2003.