What is the most likely diagnosis for a woman who believes she has moving worms in her skin despite no physical findings?

The most likely diagnosis in this scenario is delusional disorder, specifically a type known as "parasitosis," where the individual firmly believes that she is infested with parasites or worms. This belief persists despite a lack of any corroborative physical evidence or findings to support the claim. In delusional disorder, the key feature is a well-formed, fixed belief that is not shared by others in the same cultural context, indicating a significant disconnect from reality.

In cases like this, the individual may be experiencing strong, persistent delusions, which can lead to considerable distress. These beliefs do not align with any underlying medical or physical condition, and the absence of tangible evidence corroborates the delusional nature of her perception. Treatment typically involves antipsychotic medications, as well as psychological support.

This diagnosis stands in contrast to the other disorders listed. Factitious disorder would involve intentionally producing symptoms for personal gain, which does not align with the reported experience of believing in parasites. Somatoform disorders include physical symptoms arising without a medical explanation but typically present with more varied symptoms, whereas this case centers solely on a specific belief. Generalized anxiety disorder involves excessive worry about various aspects of life, not a singular, fixed delusion of this nature