Is psoriasis associated with dementia or cognitive impairment? A Critically Appraised Topic*

Abstract

Clinical question Is psoriasis associated with dementia or cognitive impairment? Background Psoriasis is a multisystemic inflammatory disorder that has an unclear association with cognitive dysfunction. Objectives To conduct a Critically Appraised Topic that synthesizes the results from relevant observational studies. Methods A systematic literature search of PubMed and Embase was conducted on 12 July 2019 to identify case-control, cross-sectional or cohort studies that investigated the association between psoriasis and cognitive impairment or dementia. Risk of bias was assessed for each study, and the results presented in a narrative synthesis. Results Eleven studies were included for critical appraisal. Of the 11 studies, 10 compared a total of 16 574 psoriasis cases with over 45 078 controls for risk of dementia or cognitive impairment. One of the 11 studies evaluated 7118 patients with dementia for odds of psoriasis compared with 21 354 controls. Six studies were assessed to have higher risk of bias. Nine of the 11 included studies found a significant positive association between the two diseases, one study a null association, and one study an inverse association. Discussion and recommendation Most of the 11 included studies found a positive association between psoriasis and either mild cognitive impairment or dementia. Brief cognitive assessments have been suggested to screen older patients with psoriasis who present with subjective cognitive complaints. What is already known about this topic? • Psoriasis and dementia are complex diseases with multifactorial pathogenesis, but share common inflammatory characteristics. • There is evidence for a shared genetic and inflammatory pathogenesis between the two entities. What does this study add? • Most observational studies found a significant positive association between psoriasis and cognitive impairment or dementia, and cognitive screening can be considered for patients with psoriasis who present with cognitive complaints. • There is currently not enough evidence to suggest one specific systemic antipsoriatic treatment over another for patients with psoriasis showing mild cognitive impairment or dementia.

Prevalence and risk factors for cognitive impairment in patients with psoriasis

“…Guilt and self-blame have been reported among the emotions experienced by parents of children with atopic dermatitis (AD). 3 In this cross-sectional study, which included 1063 parents of children with AD between 6 and 17 years old selected from a representative sample of the French population, we observed that 251 parents (23.6%) reported that they felt guilty for their child's AD. The fact that the recruitment did not take place in a hospital or in dermatological practice may allow to detect parents of patients who were diagnosed with AD, but who do not go regularly to the hospital or to the dermatologist, since, for example, they have a mild condition.…”

“…For example, in patients with psoriasis, 5 it was studied as a component of feelings of stigmatisation. To our knowledge, with the exception of the qualitative study by Chamlin et al, 3 the presence of feelings of guilt in parents of patients with AD has not been investigated. Our observation that such feelings are present in about a quarter of parents of children with AD shows that this aspect cannot be neglected.…”

A preliminary study about neurofilament light chain and tau protein levels in psoriasis: Correlation with disease severity

“…Psoriasis has been found to be associated with an increased risk of cognitive impairment and dementia in most studies 30 . Marek‐Jozefowicz et al performed a cross‐sectional study to evaluate cognitive function in 97 severe psoriasis cases and 91 controls.…”

Epidemiology of Psoriasis and Comorbid Diseases: A Narrative Review

“…Two systematic review and meta-analyses summarized the association between dementia and psoriatic disease (Table 3) (92,93), however two population-based studies in Taiwan found contradictory results on the association between psoriasis and dementia (100,101). Phototherapy and systemic treatment might not have a protective effect against dementia in psoriatic patients (100).…”