Delusion Delusions of infestation 2023-07-28T13:55:40Z This may occur in conjunction with tactile hallucinations of bugs or insects crawling on one's skin and is related to substance use disorders (delirium tremens). Ekbom's syndrome A persistent belief that a person is infested with living or non-living pathogens, such as parasites, insects, or bugs, when no such infestation is present.