LAUSR

The relationship of skin disease with sleep disturbance has long been appreciated, and psoriasis is prominent among the skin conditions associated with sleep disturbance. A body of quantitative research has increasingly recognized the complex biopsychosocial and neuropsychoendocrine mechanisms operating in patients with psoriasis and sleep disturbance. The relationship appears to be bidirectional, and the complexity in the relationship is illustrated by evidence for a role for sleep disturbance in the relationship of psoriasis with ischaemic heart disease and stroke. In trials of biologics, improvements in psoriasis have been accompanied by improvements in sleep parameters. The linked paper by Henry et al. in this issue of the BJD employs a qualitative methodology to explore the relationship between psoriasis and sleep dysfunction established by quantitative research. In doing so it provides a deeper understanding of the sleep-related experiences of people with psoriasis. This includes considerations of the effects of discomfort, itch and demanding treatment regimens on sleep. Henry et al.’s study then goes beyond these physical factors to provide an understanding of the interplay of physical, psychological and social factors in patients’ sleep disturbance. The strong impression is of psoriasis-related insomnia being a more complex clinical scenario than is primary insomnia. The clinical implication is of psoriasis-associated sleep disturbances presenting singular management challenges. The Common Sense Self-Regulation Model (CS-SRM) adopted by the authors provides a coherent framework for organizing and understanding the operation of multiple factors and interactions in the psoriasis–sleep relationship. Specifically, conceptualizing the relationship through the CS-SRM prism of participants’ illness perceptions has helped to understand the interplay of emotional and cognitive processes in precipitating and maintaining sleep disturbance and in modulating sleep disruption effects on daily function, quality of life, psychological well-being, and coping (as well as on the severity of the psoriasis itself). Henry et al.’s approach has also allowed for the emergence of themes not encompassed in the CS-SRM framework. It is here that the study provides an intriguing finding that may have implications for psoriasis management. Henry et al. found that participants’ attempts to obtain control of their sleep through self-management (a facet of their experience explored within the CS-SRM framework) were inhibited by ‘metacognitive techniques’. Metacognitive attempts to suppress intrusive thoughts (and replace them with more relaxing cognitions) could, paradoxically, result in increased arousal – and, thus, worsening of the insomnia that the participants were using metacognitive techniques to address. As the authors suggest, this raises the issue of potential efficacy of formal cognitive behaviour therapy and mindfulness training in management of sleep disturbance in those with psoriasis. Trials of these therapies in psoriasis are indicated. An overall implication of Henry et al.’s findings of complexity in sleep disturbance in psoriasis is a need for multidisciplinary care to address the sleep disturbance. Dermatologists should work collaboratively with psychologists, general practitioners and, in some circumstances, sleep physicians to improve the sleep of patients with psoriasis and insomnia.