Less than half of psoriasis patients referred by dermatologists to rheumatologists for suspected psoriatic arthritis (PsA) are subsequently diagnosed with the disease, an international survey has shown.
This seems to be because the vast majority are referred from other specialties, mostly dermatology and primary care, “without any standardised referral instruments,” according to findings of the study published in The Journal of Rheumatology.
The findings are based on survey responses from 149 members of GRAPPA (Group for Research and Assessment of Psoriasis and Psoriatic Arthritis), including 113 rheumatologists from 37 countries and 26 dermatologists from 16 countries.
Most dermatologists (81%) reported using PsA-specific screening instruments for psoriasis patients with suspected PsA, with 67% of suspected cases later confirmed.
However, rheumatologists said that nearly three-quarters (73.2%) of suspected PsA referrals had not been screened for the disease by primary care physicians and dermatologists and that just 48% of cases were later confirmed.
The study authors noted that the discrepancy between the number of dermatologists reporting the use of screening tools and those used in rheumatology referral practice could be down to differences in clinical practice between community-based and GRAPPA dermatologists.
“The latter are commonly expert specialists based in university care centres, with a particular interest in psoriasis/PsA, and therefore may be more likely to employ PsA screening tools,” they said.
“It is also possible that this disparity is elucidated by the fact that a substantial share of patients were referred to rheumatology by alternate routes, such as primary care and self-referral”.
Nevertheless, “the overall rates low rates of screening instrument usage reported by rheumatologists are striking”, particularly given current guidelines and the push for earlier diagnosis of the condition for better outcomes.
Screening is key, but clinician assessment also crucial
“Effective use of screening tools represents a prerequisite for early PsA recognition. Current evidence highlights that such instruments can play an important role in PsA screening across primary care and dermatology clinic settings”, the authors noted.
However, such tools are still limited, and both rheumatologists and dermatologists agreed that they are insufficient to make a PsA diagnosis alone; around 80% of clinicians surveyed felt that a combined approach based on both patient-reported information and physician-confirmed findings “represents the optimal means of identifying PsA in psoriasis patients”, the paper noted.
“Screening instruments could initially be used to accurately and quickly exclude patients without PsA, thus reducing rates of inappropriate referral to rheumatologists … Subsequently, physician-confirmed findings could help facilitate differentiation of PsA from other arthritic diseases,” the investigators said.
In Australia a 2015 study (link here) found the prevalence of undiagnosed PsA in patients with psoriasis to be 9%, and there have been recommendations that patients with psoriasis be screened for PsA using tools such as the Psoriasis Epidemiology Screening Tool (PEST). However the study authors noted the positive predictive value of such screening tools was low.
The survey also revealed that the most significant unmet needs regarding earlier disease diagnoses were educating dermatologists and primary healthcare professionals and raising awareness of the increased risk of PsA and related symptoms among patients.
“Targeted clinician education on the recognition of signs and symptoms suggestive of PsA, alongside the creation of an early recognition protocol that considers screening tools and examination findings, are seen as important steps that will optimise PsA screening,” according to the authors.