Can atopic eczema and psoriasis coexist? A systematic review and meta‐analysis

Abstract

Importance: Previous studies report both coexistence and mutual exclusivity of atopic eczema (AE) and psoriasis, but these have not been appraised systematically. Knowledge of such disease association throws light on disease mechanisms and may influence therapeutic choices. Objective: To summarise evidence for AE and psoriasis occurring in the same person at the same point in time. Planned primary outcome was the incidence, prevalence or risk of psoriasis or eczema. Methods: Ovid MEDLINE and Ovid Embase were searched from inception to 1st February 2020. The search strategy was built around the key terms 'atopic eczema', 'psoriasis' and 'co-existence'. Observational studies (cohort, case-control, cross-sectional and case-series) with a minimum of 10 consecutive patients were included. There were no restrictions on participants, geography or language. Studies were selected, data extracted and critically appraised by two independent reviewers. Data were extracted on the method of diagnosis: health professional (dermatologist, criteria, other), self-reported, not specified. Study quality was assessed using validated Joanna Brigg's Institute critical appraisal tools. A random-effects model was used to combine studies. The effect of study quality on the pooled estimate was investigated using stratification. Heterogeneity was explored by subgroup analysis. Results: This review included 31 studies and 20 523 individuals with psoriasis and 1 405 911 with AE. Eight studies reported the prevalence of AE in those with psoriasis and values ranged from 0.17% to 20%: the pooled prevalence was 2% (95% confidence interval [CI]: 1, 3). Seven studies reported the prevalence of psoriasis in those with AE and values ranged from 0.3% to 12.6%; the pooled prevalence was 2% (95% CI: 1, 3). Ten studies were assessed as low risk of bias. Geographical area, method of diagnosis, setting and whether the assessment of diagnosis was blinded, partly contributed to the heterogeneity. Conclusions: This review provides some evidence for the coexistence of AE and psoriasis. Clinicians should be aware of coexistence at diagnosis, when selecting therapies and when reviewing poor response to treatment.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

New onset atopic dermatitis and psoriasis in the same patients under biologic treatments: The role of systemic treatments as a possible trigger

“…Being two diseases characterized by different pathways, as PsO is predominantly Th1 while AD predominantly Th2, different authors reported a mutual exclusivity of both diseases 3, 4 . However, other observational studies have supported the coexistence of AD and PsO, reporting conflicting relationships between other Th2 and Th1 diseases 3,5 . Indeed, Cunliffe et al 3 in a systematic review found that coexistence of AD and PsO may be present, and evaluating 31 papers (20,523 individuals with PsO and 1,405,911 with AD), found that the prevalence of AD in patients with PsO has values from 0.17% to 20% with a pooled prevalence of 2%, while the prevalence of PsO in patients with AD ranged from 0.3% to 12.6% (pooled prevalence 2%) 3 .…”

“…other observational studies have supported the coexistence of AD and PsO, reporting conflicting relationships between other Th2 and Th1 diseases. 3,5 Indeed, Cunliffe et al 3 in a systematic review found that coexistence of AD and PsO may be present, and evaluating 31 papers (20,523 individuals with PsO and 1,405,911 with AD), found that the prevalence of AD in patients with PsO has values from 0.17% to 20% with a pooled prevalence of 2%, while the prevalence of PsO in patients with AD ranged from 0.3% to 12.6% (pooled prevalence 2%). 3 Our report shows how PsO and AD may be also metachronous cutaneous diseases, that can arise in the same patients, regardless of whether undergoing systemic or topical therapy.…”

“…1,2 In the literature, usually AD and PsO are reported as two diseases that cannot coexist in the same patient because this requires the activation of opposing inflammatory pathways, specifically Th2 in AD and Th1 in PsO. 3 However, there are also reports and systematic reviews that highlight how AD and PsO may coexist in the same patient or develop consequently 3 The aim of this study was to evaluate a subpopulation of AD and PsO patients that under systemic and topical treatments developed a coexistence of both diseases, in order to identify and describe this subcategory of patients that can be neglected and not well framed both from a pathogenic and a therapeutic point of view.…”

“…In the literature, usually AD and PsO are reported as two diseases that cannot coexist in the same patient because this requires the activation of opposing inflammatory pathways, specifically Th2 in AD and Th1 in PsO 3 . However, there are also reports and systematic reviews that highlight how AD and PsO may coexist in the same patient or develop consequently 3 …”

From Empirical to Pathogenesis-Based Treatments for Psoriasis

“…This explains why bacterial infections of the skin are seldom seen in patients with psoriasis and are frequent in patients with atopic dermatitis. Although psoriasis and atopic dermatitis were supposed to be mutually exclusive (Christophers and Henseler, 1987), atopic dermatitis and psoriasis may present in the same individual, both simultaneously and consecutively, and coexistence of disease may occur at a level equal to or lower than expected (Cunliffe et al, 2021).…”