From excoriated acne to delusional infestation: a case report of a psychodermatologic continuum

Delusional infestation is a rare psychodermatologic disorder characterized by a fixed false belief of infestation despite the absence of objective evidence. Its development from excoriated acne has rarely been documented. We report the case of a 38-year-old female who developed progressive facial lesions following adult-onset acne. Recurrent skin picking associated withobsessive-compulsive behaviors led to multiple facial excoriations and post-inflammatory pigmentary changes. Dermoscopicexamination revealed linear erosions with hypo- and hyper-pigmented areas without evidence of an underlying dermatosis orparasitic infestation. Over time, the patient developed formication and a persistent belief of infestation, consistent with secondary delusional infestation. This case highlights a psychodermatologic continuum linking excoriated acne and delusionalinfestation, emphasizing the role of psychological vulnerability in disease progression. Early recognition of excoriated acneand multidisciplinary management are essential to prevent the development of more severe psychiatric manifestations.