Delusional infestation: a clinical profile.

OBJECTIVE: Delusional infestation or delusional parasitosis is a form of monodelusional disorder, a condition sometimes encountered in psychiatric or primary care practice. The outcome of this condition is good when compliance can be ensured.

PATIENTS AND METHODS: In the present study, a series of 50 consecutive cases of delusional infestation is reported.

RESULTS: A majority of cases (94%) had insidious onset. The duration of symptoms in all but 3 cases was 6 months or more. Twenty-eight cases presented with a delusion of infestation by insects over the body and 20 cases with a delusion of insects crawling over the scalp. Two cases had associated diabetes mellitus, 3 cases had leprosy, 2 cases had dementia, 5 cases had depression, and 4 cases presented with trichotillomania. Among the second generation antipsychotics, risperidone was used in 12 cases, olanzapine in 9 cases, amisulpride in 7 cases, etc. Thirty-four cases (68%) showed complete remission while receiving pharmacotherapy, 13 cases showed partial improvement, and 3 cases did not respond to treatment.

CONCLUSIONS: The study demonstrates the utility of second generation antipsychotics in the treatment of this disorder. Further studies are warranted to study the treatment and outcome of this important psychiatric disorder.