of the disease and limit the burden of the disease and its impact on QoL and the ability to work.7
The multifactorial pathophysiology of psoriasis involves genetic, environmental, and immunologic factors.8,9 Psoriatic lesions are characterized by inflammation, epidermal hyperproliferation, abnormal keratinocyte differentiation, and skin barrier dysfunction.8-10 Inflammatory skin diseases are often associated with skin barrier dysfunction; although the cause-and-effect relationship is complex.9 Psoriasis and gene mutations within the epidermal differentiation complex are associated with development, maturation, cornification, cross-linking, and thermal differentiation.9-12 Alterations to several structures in the epidermal barrier in psoriasis might be responsible for barrier dysfunction leading to hyperproliferation of the epidermis.9,10
Skincare is rarely mentioned in published guidelines and algorithms to treat psoriasis, unlike atopic dermatitis.13-15 There is a knowledge gap concerning using moisturizers, either alone or as adjunctive therapy, to restore skin barrier function, reduce symptoms, and delay relapse in patients with psoriasis.15 This review aims to summarize aspects of skin barrier dysfunction in patients with psoriasis and to provide insights into the role of gentle cleansers and moisturizers in managing psoriasis and promoting a healthy skin barrier and better patient outcomes.
MATERIALS AND METHODS
On July 21, 2022, an expert panel composed of 6 dermatologists (5 American and 1 Canadian) who commonly manage psoriasis patients was convened in Vancouver, British Columbia, Canada. The panel used the Delphi communication technique for interactive decision-making for medical projects for the review.12,13 In preparation for the meeting, a literature review was conducted on skin barrier dysfunction in psoriasis, possible implications for the management, and the potential role of skin care.
Literature Review
A structured search of the English-language literature on skin barrier dysfunction and skincare in psoriasis was performed on June 17, 2022, using PubMed, with Google Scholar as a secondary source. The search included literature on skin barrier function in psoriasis, possible implications for managing psoriasis patients, and the use of nonprescription skincare, including cleansers and moisturizers as adjuncts to prescription treatment. Guidelines, consensus papers, and reviews published in English from 2010 to September 2022 were included in the search. Articles with no original data (except in cases where a review was the best available evidence), articles on prescription therapy alone (without discussion of nonprescription skin care), and publication language other than English were excluded from the search.
Search terms used: Psoriasis AND skin barrier function(s); OR Psoriasis AND skin barrier dysfunction; OR Psoriasis AND skin lipids AND ceramides; OR Psoriasis prescription treatment AND cleansers; OR Psoriasis prescription treatment AND moisturizers; OR Psoriasis AND OTC skincare; OR psoriasis AND skincare efficacy, safety, tolerability.
The searches yielded 41 clinically relevant papers (12 guidelines, algorithms, and consensus papers, 12 reviews, 2 randomized controlled trials, 8 clinical studies, 4 epidemiology, and Qol studies, and 3 other studies) to inform current best practices in psoriasis patients and skincare use. (Table 1 and Table 2). Robust comparative studies on skincare used as monotherapies or adjuncts to prescription topical and systemic therapies are scarce and did not allow for a systematic review.
RESULTS
In a workshop, the authors provided feedback on 15 statements created before the meeting and agreed upon 5 statements to offer expert guidance for gentle cleansers and moisturizer use in psoriasis patients.
Statement 1: Inflammatory skin diseases are often associated with barrier defects, although the cause-and-effect relationship is complex in psoriasis and requires further studies.
Psoriasis, an immune-mediated disease, is associated with comorbidities, such as psoriatic arthritis, metabolic syndrome, diabetes, and cardiovascular disease.8 Psoriasis comprises multiple phenotypes that can be generalized or localized.13,16-18 The pathophysiology of psoriasis is complex and includes many cytokines and signaling pathways9-12 Research has led to insights into the psoriasis disease pathway, including the role of the tyrosine kinase 2 (TYK2) pathway.19,20 The TYK2, a protein-coding gene, has been identified as part of the psoriasis susceptibility loci and is linked to interleukin (IL) -23 signaling.19,20 TYK2 plays a critical role in the IL-23/IL-17 inflammatory axis, which is central to the pathophysiology of psoriasis.11,19,20 Inflammatory skin diseases such as psoriasis are often associated with epidermal barrier dysfunction, although the cause-and-effect relationship is unclear and requires further studies.9-12,16-22 Alterations to epidermal differentiation complex genes and several structures in the epidermal barrier in psoriasis may be responsible for the hyperproliferation of the epidermis in an attempt to repair the skin barrier.10,16-22
Stabilization of the skin barrier depends on intact keratinocytes and physiologic lipid synthesis. Depletion of ceramides in the stratum corneum has been reported in patients with psoriasis.23-25 Animal studies and clinical studies that take skin biopsies from patients with psoriasis have suggested that ceramides play a relevant role in the pathophysiology of psoriasis.23-25 However, data on moisturizers containing ceramides for psoriasis, either
