Management of patients with delusional parasitosis in a joint dermatology/ liaison psychiatry clinic

Conflicts of interest: none declared. Sir, Delusional parasitosis (DP) is a well‐recognized uncommon difficult condition. Patients with DP hold a fixed belief that they are infested with organisms. When referred to a psychiatric clinic, patients with DP will often default on appointments.1 Conversely, due to time and experience resources, it is also difficult to manage these patients in a standard dermatology clinic. In 2002, we established a joint dermatology/liaison psychiatry clinic, to which patients are referred from primary and secondary care. We report findings in our practice for 3 years (January 2004–January 2007). The term delusional parasitosis, first coined by Wilson and Miller in 1946,2 has been known by various names.3, 4 It can be subdivided into primary and secondary disorders,5, 6 and is uncommon7 with an annual incidence of 20 cases per million.8 The female to male ratio is reported as 2 : 1.9 There is a bimodal distribution with a peak between 20 and 30 years and at > 50 years,10 and there are frequent reports of the delusions being shared by a relative or friend (folie‐à‐deux; 8–12% of cases of DP),9, 11 or by more than one person (folie‐à‐trois).12