A case series of shared delusional infestation: folie à deux revisited

Delusional infestation describes the unshakeable belief that one's skin is infected or infested with an external organism or inanimate material, in the absence of supportive medical evidence. It is one of the most challenging psychodermatological conditions to manage, given the rigidity of patients’ physically focused health beliefs, and the competing need to introduce antipsychotic therapy to bring about resolution. This is rendered exponentially more complex when partners or family members are similarly afflicted. This situation is known as shared delusional infestation, shared psychotic disorder (SPD), or folie à deux. We present a series of three couples with SPD who were referred to our tertiary psychodermatology service during the same year. On examining the literature we were intrigued to discover that subtly different subtypes of SPD have been recognized since the late 1800s. These include folie simultanée, imposée, communiquée and induite. Our cases neatly demonstrate three of these variants, and highlight the difficulties in facilitating effective treatment.     

Use of the Dermatology Life Quality Index work/study domain to estimate overall work productivity loss among patients with psoriasis: an analysis based on real-world data

Psoriasis is a chronic autoimmune disease that is associated with substantial economic burden related to work productivity loss (WPL). WPL is commonly measured using the Work Productivity and Activity Impairment (WPAI) questionnaire. However, WPAI does not measure outcomes among unemployed patients, and may therefore underestimate the burden of psoriasis. This study evaluated the relationship between the Dermatology Life Quality Index (DLQI) questionnaire work/study domain and WPL using the WPAI, as DLQI assesses the impact of psoriasis on the ability to work/study regardless of employment status, but does not estimate WPL. Data were drawn from the Adelphi Psoriasis Disease Specific Programme survey. A positive linear relationship was observed between DLQI work/study scores and WPAI results, showing that higher DLQI scores were associated with greater percent WPL. These findings suggest that the DLQI work/study domain can be used to estimate overall WPL among patients with psoriasis, including those who cannot work because of their disease.