BackgroundDementia with Lewy bodies (DLB) is characterized by fluctuating cognitive impairments, recurrent visual hallucinations, the motor symptoms of parkinsonism and REM sleep behavior disorder. Various neuropsychiatric symptoms including hallucination and delusions occur frequently; however, delusional parasitosis is rare in DLB. Here, we report a case of DLB patient with delusional parasitosis.Case presentationThe patient was an 89-year-old woman. At the age of 88, she began to complain her oral cenesthopathy, and developed cognitive decline, delusional parasitosis and parkinsonism. As a result of examination, she was diagnosed as DLB and treated with combination of donepezil 5 mg/day and aripiprazole 1.5 mg/day, and her complaint was disappeared.ConclusionsFurther studies are needed to investigate the association between delusional parasitosis and underlying pathophysiology of DLB, and the utility of antipsychotics for delusional parasitosis in DLB has to be examined through more cases.

Clozapine is an atypical antipsychotic used for treatment‐resistant schizophrenia and is known to cause serious side effects, such as leukopenia and neutropenia. We encountered the case of a 44‐year‐old female patient with a good response to clozapine, who experienced inflammatory reaction and cytopenia after coronavirus disease 2019 (COVID‐19) vaccination. Soon after clozapine discontinuation, the inflammatory reaction resolved, and cell counts recovered. There are only a few reports on the interaction between clozapine and COVID‐19 vaccine. Our findings suggest that caution is required when a patient who is receiving clozapine scheduled for COVID‐19 vaccination, owing to the possibility of cytopenia. Moreover, blood tests and the measurement of clozapine concentration should be performed before and after the inoculation to ensure patient safety.