Review
Special site psoriasis and psoriatic arthritis: environmental triggers and disease interplay. A systematic review
W. Kruczek1, A. Mandecka2, M. Kalicka3, B. Jelonek4, A. Frątczak5, B. Berler-Czop6, B. Miziołek7
- Students‘ Scientific Association at the Department of Dermatology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland.
- Students‘ Scientific Association at the Department of Dermatology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland.
- Students‘ Scientific Association at the Department of Dermatology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland.
- Students‘ Scientific Association at the Department of Dermatology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland.
- Department of Dermatology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland.
- Department of Dermatology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland.
- Department of Dermatology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland. bmiziolek@sum.edu.pl
CER14
Review
Received: 09/06/2025
Accepted : 01/09/2025
In Press: 17/09/2025
Abstract
OBJECTIVES:
Psoriatic arthritis (PsA) is a chronic inflammatory musculoskeletal disease affecting approximately 20-30% of patients with psoriasis (PsO). Early identification of PsA risk factors is essential to prevent irreversible joint damage. Psoriasis involving “special sites” such as the nails, scalp, hands, feet and anogenital region has been increasingly linked to elevated risk of development for PsA. This systematic review aimed to assess the evidence for a correlation between special site psoriasis and PsA onset and to evaluate whether this relationship is coincidental or biologically driven.
METHODS:
A comprehensive literature search of PubMed, Cochrane Library and Embase databases through April 2025 identified 26 studies meeting PRISMA criteria. Search terms included “Psoriasis,” “Psoriatic Arthritis,” and location-specific descriptors (e.g. “Scalp Dermatoses,” “Nail,” “Foot Dermatosis,” “Hand Dermatosis,” “Intergluteal Lesions” or “Perianal Lesions”). Eligible studies focused on associations between psoriasis at special sites and PsA development. The certainty of evidence was assessed using the GRADE approach. The review protocol was prospectively registered in the PROSPERO database (registration ID: CRD420251090316).
RESULTS:
Of the 26 included studies, 19 examined nail involvement, with 17 showing a positive association with PsA. Imaging techniques such as high-frequency ultrasound and capillaroscopy confirmed inflammatory and structural changes in the nail-entheseal complex. Scalp psoriasis was evaluated in nine studies; four supported a correlation with PsA. Five studies assessed genital and intergluteal/perianal involvement, with four showing a significantly increased PsA risk.
CONCLUSIONS:
The involvement of nails shows the strongest association with PsA development, likely due to anatomical and functional continuity between the nail apparatus and the enthesealjoint interface. Scalp psoriasis may reflect or exacerbate systemic inflammation, although available data remains inconsistent. Anogenital psoriasis appears to signify a distinct immunopathological phenotype shaped by its unique microenvironment. Importantly, a range of environmental triggers including mechanical trauma, moisture and occlusion, microbial dysbiosis, chemical and biological irritants, seasonal and climatic influences, smokingand alcohol-induced immune modulation, UV radiation, and obesity-related metabolic inflammation may modulate immune activation at these sites and contribute to PsA onset. These findings support a biologically driven interplay between site-specific skin inflammation and joint involvement, mediated in part by local environmental influences.
