PS07 Delusional infestation: are delays in access to care adversely affecting patient outcomes? A case series

Abstract

Delusional infestation (DI) is the fixed, false belief of pathogenic infestation of the skin or body, despite no supporting medical evidence. Patients may be difficult to treat successfully, because of their reluctance to accept referral or involvement of psychiatric services. Research consistently supports assessment of this cohort in multidisciplinary psychodermatology clinics, where integrated medical and psychiatric care can be seamlessly provided. The British Association of Dermatologists (BAD) All Parliamentary Group has recommended increased psychodermatology services across the UK, but provision is still scanty. We report a review of 49 consecutive patients (12 men and 37 women) with a diagnosis of DI assessed in a regional psychodermatology service. Mean patient age was 63 years (range 41–92). Mean duration of symptoms before attending was 4.9 years. Forty-one (84%) patients complained of living creatures, with the other eight (16%) perceiving fibres or other inanimate objects. Perception of nonliving mater­ial was strongly associated with substance misuse. Low-dose antipsychotics were prescribed in 44 (90%) patients. Risperidone (n = 39; 89%) and olanzapine (n = 5; 11%) were the drugs prescribed. Medications were well tolerated, with no significant adverse side-effects reported. Twenty-three (47%) responded to treatment. Four patients developed full-blown psychotic disorders. We were unable to engage 13 (27%) patients in treatment, and in three (6%), the treatment outcomes were unknown. Responders had a mean time to presentation of 3.7 years vs. nonresponders who had symptoms for an average of 5.9 years. Ten (20%) patients admitted to current or previous substance misuse. Twenty-one (43%) had a history of psychiatric disease. Substance misuse and established psychiatric disorders were associated with poorer engagement and response. Response to treatment and engagement with services is multifactorial. This review demonstrated that delays in presentation are associated with poorer outcomes (Romanov DV, Lepping P, Bewley A et al. Longer duration of untreated psychosis is associated with poorer outcomes for patients with delusional infestation. Acta Derm Venereol 2018; 98:848–54). In 2016, early intervention in psychosis services was introduced as a National Institute for Health and Care Excellence standard in the UK. In psychiatry, there is well-established evidence of the relationship between delays in treatment of psychosis and poorer outcomes. The BAD guidelines have recently been published to encourage more widespread prescribing of low-dose antipsychotics to expedite treatment. Our review highlights that all patients with DI face significant delays to treatment, which may adversely impact or increase the complexity of clinical presentations. This review emphasizes the importance of early assessment and supports the expansion of psychodermatology services.