Annals of Indian Psychiatry

: 2019  |  Volume : 3  |  Issue : 1  |  Page : 55--57

Clinical presentation of delusion of parasitosis in a tertiary care center

Hemang Manaharbhai Shah, Mahemubin Lahori, Prakash Mehta 
 Department of Psychiatry, GMERS Medical College, Sola, Ahmedabad, Gujarat, India

Correspondence Address:
Dr. Mahemubin Lahori
Department of Psychiatry, GMERS Medical College, Sola, Ahmedabad, Gujarat


Background: Delusional parasitosis is a relatively uncommon psychiatric condition. Owing to its low prevalence there is limited research in this area. The present cross sectional study was conducted to study clinical presentation, belief and response of patients of delusion of parasitosis in a general hospital over a period of January 2017 to September 2017. Methods and Materials: 40 new patients who presented to psychiatry OPD with primary complaint of crawling sensation under skin were enrolled. Results: The delusion of parasitosis was seen more in females and those who were illiterate. The symptom was localized to the face or scalp. Dermatologist was the physician of contact for 59% of the patients. Comorbid depression and anxiety were also seen. Conclusion: The symptom of parasitosis was not uncommon but liaison with dermatologist is necessary for early diagnosis and management.

How to cite this article:
Shah HM, Lahori M, Mehta P. Clinical presentation of delusion of parasitosis in a tertiary care center.Ann Indian Psychiatry 2019;3:55-57

How to cite this URL:
Shah HM, Lahori M, Mehta P. Clinical presentation of delusion of parasitosis in a tertiary care center. Ann Indian Psychiatry [serial online] 2019 [cited 2023 Mar 23 ];3:55-57
Available from:

Full Text


Delusional parasitosis is a distressing condition in which the individual feels that insects are crawling under or over the skin. The belief is usually held with delusional intensity (though the severity and duration of the delusional intensity may vary).[1],[2] Often individuals with delusional parasitosis consult dermatologist and based on negative findings (clinical and laboratory), they are referred to psychiatrists for further management. The prevalence of delusional parasitosis is estimated at 80 cases per million, with a yearly incidence of 20 per million.[3] Owing to its low occurrence, the research in this area is limited. The present study was done to see the sociodemographic and clinical characteristics of persons diagnosed with delusional parasitosis in the psychiatry outpatient unit of a general medical setup in India.


The present study was conducted at a medical college attached with tertiary care center after obtaining permission from the Ethics Committee. From January 2017 to September 2017, all the patients diagnosed with delusional parasitosis at the outpatient department of the psychiatry wing were included in the study. The diagnosis based on DSM-IV-TR clinical interview techniques, and by evaluating negative history, other major psychiatric disorders were excluded from the study. A total of 40 patients during this period were diagnosed to have delusional parasitosis. Out of this, one patient was excluded as he was not willing to be interviewed in detail. Written informed consent was obtained from all the participants. Detailed sociodemographic and clinical data were gathered which included age, sex, educational level, family type, employment, and marital status.


[Table 1] shows sociodemographic and disease-related characteristics of the patients.{Table 1}

The average age of the patients was 57 years. Majority of the patients were Hindus (97%). As shown in [Table 1], majority of the patients were female, married, uneducated, and belonged to joint families. Further, 44% had the onset of the illness in the past 1–12 months.

Face, scalp, or nose was the most common affected area in 59% cases [Table 1].

Majority of the patients (59%) consulted a dermatologist first. Only 3 (7%) patients approached a psychiatrist directly. Further, only 7 (18%) patients reported the occurrence of any stressful condition before parasitosis [Table 1].

We have kept provisional diagnosis of delusion of parasitosis for those patients who were not fulfilling the duration criteria (seven patients). Only two patients reported that they had past history of similar complaints and three patients had reported that similar illness was seen in their community.

About 25% of the patients reported that they had tried household remedies, shaving, over-the-counter medicine, or massage with oil or skin ointment to get relief. Approximately 15% of the patients tried to find out the reason for having current symptoms, that is, insect entered in the body by the orifice of the ear, nose, or outcome of bad karma.

Sixteen (41%) patients had the diagnosis of delusional parasitosis alone, whereas 8 (20%) had comorbid depression, 10 (26%) had anxiety disorder, and 5 (13%) had somatoform disorder.

A total of 10 (25%) patients reported that they were able to see the insect, whereas rest (75%) could only feel [Table 2].{Table 2}


A previous study from India reported 52 cases in 7 years from a general medical setup,[4] whereas we found 40 cases from a similar setup in a duration of 9 months. It indicates that parasitosis is not so uncommon in general medical setups, and the real prevalence may be more than what has been observed in the past. This may be because of the increase in health awareness among the general public along with increase in availability of health services or a cultural reason which need further study.

Majority of the patients presented with long-standing history and had multiple visits;[5],[6],[7] however, in our study, 62% of the patients had a duration <1 year. This may be awareness regarding health or easy availability of medical services.

As expected, majority of the patients approached dermatologists first.[8] Interestingly, only in minority of the patients, any stressful event preceded the onset of delusional parasitosis. It indicates that there is need for further studies to explore the psychosocial factors (such as personality and cognitive distortions) behind the genesis of delusional parasitosis.

In the present sample, overall, the number of females was higher than males;[9] however, under 50 years age, more patients were male. Also, most of the patients were uneducated. The finding of preponderance in females is consistent with previous studies which have reported delusional parasitosis being more prevalent among females.[4],[7] Although, in general, education and mental illnesses may not have a direct relationship, in case of delusional parasitosis, our findings indicate that illiterate individuals could be vulnerable to develop this condition.

So far, as the localization of parasitosis is concerned, majority of the patients reported it to be localized to the face (specifically nose) or scalp. This finding is contrary to a previous study, in which majority of patients had reported it to be generalized to all over the body and only a few reported it to be restricted to any particular part of the body.[4] Patient's effort to know the reason of illness and from where it entered in the body is related to Hindu religio-cultural belief system.[10]

The belief is usually held with delusional intensity, but the severity of the delusional intensity can vary as the response to the symptoms may vary from being able to see to not being able to see, or picking up the insects to never picking them up.[1]

Majority of patients may also have comorbid psychiatric disorders, as mentioned by Srivastava et al. who also reported comorbidity of depressive and anxiety symptoms in 10 out of 22 patients in their study which emphasizes that comorbidities should be addressed.[11] Lepping et al. have reported that secondary delusional parasitosis does exist.[8]

Overall, the findings of the present study implicate that delusional parasitosis is not very uncommon in general medical setups. It is important to build a strong therapeutic alliance to ensure the compliance of patient for treatment as they may feel it is not a psychiatric condition requiring treatment from a psychiatrist.[11] Furthermore, there is need for the targeted intervention for this condition including life events, social support, as well as the development of focused psychotherapeutic approaches for further research.


Dr Devvarta Kumar, Professor of Psychology, NIMHANS, Banglore.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


1Ramin M, Laura JF, Evelyn JB. Other psychotic disorders. In: Sadock B, Sadock V, Ruiz P, editors. Comprehensive Textbook of Psychiatry. China: Wolter Kluwer; 2017. p. 1582-7.
2Michael BF, Maria NW. Diagnostic and Statistical Manual of Mental Disorders DSM -5. Washington, DC: American Psychiatric Publishing; 2013. p. 90-3.
3Trabert W. 100 years of delusional parasitosis. Meta-analysis of 1,223 case reports. Psychopathology 1995;28:238-46.
4Bhatia MS, Jagawat T, Choudhary S. Delusional parasitosis: A clinical profile. Int J Psychiatry Med 2000;30:83-91.
5Levin EC, Gieler U. Delusions of parasitosis. Semin Cutan Med Surg 2013;32:73-7.
6Foster AA, Hylwa SA, Bury JE, Davis MD, Pittelkow MR, Bostwick JM, et al. Delusional infestation: Clinical presentation in 147 patients seen at mayo clinic. J Am Acad Dermatol 2012;67:673.e1-10.
7Patel V, Koo JY. Delusions of parasitosis; suggested dialogue between dermatologist and patient. J Dermatolog Treat 2015;26:456-60.
8Lepping P, Russell I, Freudenmann RW. Antipsychotic treatment of primary delusional parasitosis: Systematic review. Br J Psychiatry 2007;191:198-205.
9Wong JW, Koo JY. Delusions of parasitosis. Indian J Dermatol 2013;58:49-52.
10Srinivasan TN, Suresh TR, Jayaram V, Fernandez MP. Delusional parasitosis of body orifices-a cultural variant? Indian J Psychiatry 1993;35:218-20.
11Srivastava M, Shareef N. Varied presentation of delusion of parasitosis (DOP): A case series study. Indian J Clin Exp Dermatol 2017;3:197-202.