Alexander Egeberg, MD, PhD, on Why Screening for PsA in Psoriasis Is Key
Although estimates of the proportion of psoriasis patients who also have psoriatic arthritis (PsA) have varied widely in the past, new data published in the Journal of the American Academy of Dermatology suggest that approximately 1 in 4 patients with psoriasis has comorbid PsA.1
A Danish systematic review and meta-analysis of 266 studies with 976,408 patients with psoriasis across numerous continents found that the pooled prevalence of PsA in psoriasis was 19.7% overall and 23.8% in studies applying the Classification Criteria for Psoriatic Arthritis.
When stratified by region, PsA prevalence in European, South American, North American, African, and Asian patients was found to be 22.7%, 21.5%, 19.5%, 15.5%, and 14.0%.
Consultant360 discussed the clinical implications of these findings further with study author Alexander Egeberg, MD, PhD, of the Department of Dermatology and Allergy at Herlev and Gentofte Hospital at the University of Copenhagen in Denmark.
Consultant360: In your study, you found that 1 in 4 patients with psoriasis have PsA. Was this finding expected or surprising?
Dr Egeberg: PsA has long been recognized as one of the most frequent comorbidities in psoriasis, yet studies have produced wide variations in estimates, depending on the study size, methodology, and country. While some studies have reported even higher estimates, others have found the prevalence to be markedly lower. By examining all published articles, the finding that 1 in 4 patients with psoriasis may develop PsA during their lifetime may serve as a reminder for physicians to frequently screen for PsA symptoms in their patients.
C360: Previous evidence has suggested that PsA can often be underdiagnosed or misdiagnosed. What factors might contribute to this, and what consequences can occur if a PsA diagnosis is delayed, especially in patients with psoriasis?
Dr Egeberg: Recent data suggest that the incidence of PsA is increasing on a population level.2 While several reasons may potentially explain this, one likely cause is that physicians and patients have become much better at detecting the disease in recent years. This is of particular importance, since PsA is a chronic and debilitating disease that may cause potentially irreversible joint damage.
C360: What are the clinical takeaways of your study? How might these findings inform PsA risk assessment among patients with psoriasis?
Dr Egeberg: In our study, we found that several factors may affect the prevalence of PsA, including geographical location, psoriasis severity, and patient age. This may help clinicians when assessing an individual patient’s risk.
C360: How should physicians screen for PsA in patients with psoriasis?
Dr Egeberg: Although a rheumatologist’s assessment should always serve as the gold standard, even a brief joint inspection and palpation, and screening questions about joint stiffness, etc., may help raise the suspicion of PsA, enabling timely referral to the appropriate specialists.
- Alinaghi F, Calov M, Kristensen LE, et al. Prevalence of psoriatic arthritis in patients with psoriasis: A systematic review and meta-analysis of observational and clinical studies. J Am Acad Dermatol. 2019;80(1):251-265.e19. https://doi.org/10.1016/j.jaad.2018.06.027.
- Egeberg A, Kristensen LE, Thyssen JP, et al. Incidence and prevalence of psoriatic arthritis in Denmark: a nationwide register linkage study. Ann Rheum Dis. 2017;76:1591-1597. http://dx.doi.org/10.1136/annrheumdis-2016-210963.