Psoriasis typically predates PsA by a decade or more, therefore, skin involvement offers an opportunity to study risk factors.
There is a great need to understand which patients with psoriasis might be at risk for developing psoriatic arthritis (PsA), according to Dennis G. McGonagle, PhD, FRCPI. “This is especially relevant since therapy for psoriasis that may be merited for skin disease alone could potentially prevent arthritis,” he says. “However, the literature surrounding this is controversial and it is unclear which drug classes might be best for PsA prevention.”
As PsA affects up to one third of people with psoriasis, emerging evidence indicates that a PsA diagnosis is preceded by the manifestation of imaging abnormalities and arthralgia, Dr. McGonagle points out. “Psoriasis typically predates PsA by a decade or more,” he says, adding that skin involvement offers an opportunity to study risk factors and predictors of PsA development and its preclinical phases. “The rate of evolution from psoriasis to PsA is low and defining factors linked with the imminent development of PsA are needed to improve trial design,” he explains. “In addition, a definition of what constituted early PsA in patients with psoriasis was lacking.”
Defining Short- & Long-Term Risk Factors for PsA
For a study published in Annals of the Rheumatic Diseases, Dr. McGonagle and colleagues sought to frame EULARpoints to consider for the creation of data-driven guidelines for clinical practice and clinical trials with the aim of preventing or intercepting PsA, as well as the clinical management of patients with psoriasis at risk for developing PsA.
The study team examined factors linked with PsA development in people with psoriasis and used the EULAR methodology, including systematic literature reviews, to guide the taskforce. “We undertook the same process to evaluate how PsA presents in people who are receiving follow-up care for psoriasis,” Dr. McGonagle points out. “We emphasized that some risk factors for PsA, such as nail disease and obesity, are long-term risk factors, but symptoms such as joint pain, imaging abnormalities, or both, are short-term predictors.”
Three stages relevant to the prevention of PsA were identified, Dr. McGonagle notes (Figure):
- Higher risk stage: People with psoriasis at risk for PsA (lasts an average of 7-12 years)
- Subclinical stage: Imaging features are typically linked with more imminent progression to PsA (1-3 years)
- Clinical stage: Defined by the presence of clinical synovitis (joint swelling) in a patient with psoriasis, which is equivalent to early PsA
Examining Lifestyle Habits or Using Systemic Treatment
“Our research sets the scene for prevention studies for patients with PsA with newly developed synovitis,” Dr. McGonagle says. “For future research, good longitudinal data collection and trials to discover optimal ways to prevent PsA are key. An important consideration is how to deal with patients with mild psoriasis, as these cases are not eligible for systemic therapy for the skin.”
Dr. McGonagle and colleagues concur that their study “will facilitate research investigating the stages preceding clinical PsA and the opportunity to prevent PsA development by modifying lifestyle habits or using systemic treatment that could act both on the skin and the joint to prevent PsA development.”