In the case of delusory parasitosis, what is notable about the physical cause?

In delusory parasitosis, the key characteristic is that there is no external, physical cause for the sensations or beliefs that a person is experiencing parasites or insects infesting their skin. This condition is classified as a psychological disorder where individuals firmly believe they are infested despite a lack of any confirmatory evidence or real infestation. Health professionals often find that thorough examinations reveal no parasites, supporting the notion that the symptoms are rooted in a cognitive or perceptual issue rather than a tangible external source.

The absence of a verifiable physical cause is crucial for understanding the nature of delusory parasitosis, as it distinguishes the condition from genuine infestations where physical evidence would typically be present. While cases can vary in duration and some might persist temporarily, the defining feature remains the lack of any identified external cause tied to the delusions of being infested.