Delusional parasitosis: Worms of the mind
A 36-year-old male was apparently asymptomatic until August 16, 2011, when, in the background of vague sensation of something crawling under his skin, he developed a sudden onset belief that he has been infested by worms that crawl under his skin as well as travel throughout his body. Over next few days, he experienced these sensation again with which he reinforced his belief to an unshakeable level of delusion, although there were no physical feature suggestive of an infestation or any logical ground for holding his belief with such conviction. He started pinching his skins to get hold of those worms. He believed these worms to be of 3-7 cm in length and numerous in numbers. He believed that these worms were biting him, damaging his internal organ, and eating his bone and that they would finally kill him. He became fearful and sought help from a physician. He was prescribed tablet albendazole, which provided him no relief. He further consulted another physician. Routine hemogram and urinalysis was unremarkable. He was given antihelminthic and antiallergens to no relief. He was counseled that he does not have an infestation and his complaints had no physical explanation; however, he held on to his belief regardless. He lost his appetite, remained anxious, and slept less. He was noted by his treating physician to be dull and withdrawn, which led to the psychiatric referral. There was history of hepatitis A 2 months back, which had responded to management by physician and local faith healer. There was no history of pruritis during and after the recovery from hepatitis. There was no past or family history of any neurological, psychiatric, endocrinal, chronic, or allergic illness. He consumed alcohol occasionally. There was no history of any other substance abuse. Physical examination on admission did not reveal any feature of active hepatitis or thyromegaly. Systemic examination was within normal limit. Skin examination revealed itch marks and skin excoriations both the limbs and on other accessible parts of the body. Mental status examination revealed anxious and depressed affect, delusion of parasitosis, tactile hallucination, impaired insight, and reduced biodrives in a clear sensorium. He was admitted in the psychiatry ward for inpatient management. Serial evaluation and ward observation revealed persistent delusion of parasitosis, delusional, and hallucinatory behavior of picking the skin in an attempt to catch the worm, intermittent wincing as he felt worms bit him, secondary depressive cognition, initial insomnia, and reduced appetite. Relevant investigations including hemogram, urinanalysis, fecal analysis, thyroid function, liver function, VDRL, blood sugar, ultrasonography abdomen, viral marker for active hepatitis, electroencephalogram, and computed tomography of the brain was within normal limit. He was also evaluated by dermatologist and physician for evaluation and exclusion of any organicity. He was subsequently diagnosed as a case of persistent delusional disorder (monosymptomatic hypochondriacal psychosis-delusional parasitosis) as per International Classification of Disease (ICD-10-DCR) and managed with typical antipsychotic trifluperazine (10 mg/day), eclectic psychotherapy, and other supportive measures. His delusion and hallucination subsided over the next 2 weeks. He was discharged after 5 weeks on maintenance medication. He has subsequently been asymptomatic and euthymic. Presently, he is asymptomatic since last 7 months and been regular on monthly reviews.