Severe Psoriasis Skin Involvement Positively Associated with Psoriatic Arthritis Diagnosis

Patients with psoriasis (PsO) who exhibited more severe skin involvement were more likely to have a concurrent psoriatic arthritis (PsA) diagnosis, according to a study published in Karger.¹ Results emphasize the importance of collaboration between dermatology and rheumatology in clinical care.

“Early identification of patients at risk of psoriatic arthritis PsA is essential to facilitate early diagnosis and improve clinical outcomes,” investigators explained. “Severe cutaneous psoriasis has been proposed to be associated with PsA, but a recent assessment of the evidence is lacking.”

Using articles published after January 1, 2013, investigators conducted a meta-analysis that analyzed psoriasis severity, as defined by psoriasis area and severity index (PASI), body surface area (BSA), and the “number of affected sites,” to determine the association between PsO and PsA diagnosis. Eligible studies included adult patients and compared psoriasis severity between patients with PsO and without PsA (PsO-PsA), patients with PsA, and those with PsO that developed PsA. A meta-analysis was performed if ≥3 studies used a similar study design, used the same association measures, and had comparable psoriasis severity measures.

Of 2000 studies examined, 29 were ultimately included in the final analysis. A total of 17 analyzed PASI, 8 focused on BSA, 2 evaluated both PASI and BSA, and 2 assessed the number of affected sites. Results indicated that more extensive skin disease was associated with the presence of PsA. In the 13 studies included in the meta-analysis, both a higher PASI (mean difference [Δ] 1.59; 95% confidence interval [CI] 0.29–2.89) and higher BSA (Δ 5.31; 95% CI 1.78–8.83) were reported in more patients with PsA when compared with those without PsA. Results of an adjusted meta-analysis presented a smaller, yet still significant difference (Δ 1.25 [95% CI 0.55–1.95]). All studies showed that patients with PsA had higher BSA scores when compared with patients with psoriasis, which was confirmed in the meta-analysis (Δ 5.31 [95% CI 1.78–8.83]).

Based on 3 prospective studies that evaluated psoriasis severity in PsO-PsA and the eventual development of PsA, the risk of the future development of PsA was inconclusive.

The meta-analysis was limited by heterogeneity and the small number of studies. Additionally, while all applicable articles are believed to have been included due to the validated methodology, investigators did not repeat the systematic search. An overestimation of psoriasis severity in patients with PsA may have occurred as most studies were performed in dermatology clinics. Lastly, subgroup analyses, such as family history, smoking status, and obesity, could not be conducted due to limited data.

“Our results demonstrate that psoriasis severity is associated with increased likelihood of concurrent PsA,” investigators concluded. “Defining psoriasis patients at risk for PsA transition remains an important topic to facilitate early recognition and prevent irreversible joint damage. Long lasting follow-up studies are necessary to study predictors for the development of PsA in psoriasis patients.”

Reference:

Pouw JN, Jacobs ME, Balak DMW, van Laar JM, Welsing PMJ, Leijten EFA. Do Patients with Psoriatic Arthritis Have More Severe Skin Disease than Patients with Psoriasis Only? A Systematic Review and Meta-Analysis [published online ahead of print, 2022 May 12]. Dermatology. 2022;1-12. doi:10.1159/000524231