RESUMO
Delusional parasitosis is a rare condition in which the patient has a false and unshakable belief of being infested by parasites. Delusional parasitosis was classified as a subtype of monosymptomatic hypochondriacal psychosis in old literature. Though the delusion is considered to be primary, at times it is described as an elaboration of a primary pathological experience such as a tactile hallucination, paresthesia or pruritus. Although several cases of delusional parasitosis have been reported, the role of cultural belief systems and native treatments in turning an idea into a delusional disorder has not been adequately studied. This paper reports a case of delusional parasitosis in which cultural factors played a major role in shaping the delusion. The case was effectively managed with risperidone.