In patients with delusions of parasitosis, given recent literature, would you attempt to trial biologic dupilumab therapy over, or in conjunction with, standard atypical anti-psychotics if they have prominent peripheral eosinophilia or severe secondary excoriative dermatitis?

Based on the available literature, I would not recommend dupilumab instead of atypical antipsychotic therapy for primary delusional parasitosis. I would consider dupilumab only as adjunctive therapy in selected patients with marked secondary inflammatory skin disease or refractory pruritus, recognizing that current evidence supports improvement of the cutaneous phenotype rather than direct modification of delusional psychopathology. Until prospective controlled studies are available, dupilumab s...

I would not expect true primary delusional infestation to respond to systemic immunomodulatory therapies like dupilumab; however, most cases of delusional infestation that I encounter are secondary to another untreated or under-treated pruritic disease. Any patient presenting with delusional infestation warrants a thorough workup for cutaneous or systemic diseases that could cause pruritus, including inflammatory skin disease, hematologic malignancy, kidney disease, cholestatic disease, and neur...