Association between skin fungal infections and psoriasis: systematic review

Abstract

Psoriasis, a chronic immune-mediated inflammatory skin disease, has been increasingly associated with fungal infections, though the nature of this relationship remains unclear. Fungal pathogens such as Malassezia, Candida, and dermatophytes might contribute to disease exacerbation, particularly in patients undergoing immunomodulatory therapies. This systematic review aimed to examine the association between skin fungal infections and psoriasis, focusing on prevalence, risk factors, and the impact of treatments. Following PRISMA guidelines, a comprehensive literature search was conducted across PubMed, Web of Science, Scopus, and Science Direct. Studies investigating fungal infections in psoriasis patients were included, while reviews and non-English publications were excluded. Data on prevalence, risk factors, and treatment effects were extracted and qualitatively synthesized. Five studies (n≤950 patients) were included, revealing fungal infection prevalence ranging from 12% to 47%. Malassezia colonization in scalp psoriasis was reduced by IL-17 inhibitors. Onychomycosis (35.3% prevalence) was linked to diabetes, wet work, and methotrexate use. Higher Candida colonization (47%) in severe psoriasis, mitigated by apremilast. IL-17 inhibitors increased candidiasis risk (12.3%) but reduced Malassezia overgrowth. Fungal infections were found to be prevalent in psoriasis, with risk influenced by disease severity, comorbidities (e.g., diabetes), and treatment type. IL-17 inhibitors exhibited dual effects, suppressing Malassezia while increasing Candida susceptibility. Integrated dermatological and mycological assessments are recommended for optimal management. Further research should explore targeted antifungal strategies in psoriasis therapy.