E002 The Psoriasis Epidemiology Screening Tool (PEST) as a mechanism for diagnosing psoriatic arthritis in dermatology practice: 5 year follow-up data from a quality improvement project
Authors: Ahmed Sajeel , Babiker Muzna , Osama Mohammad , Ahmed Minhaz , Jobling Kerry , Hampton Philip , Thompson Ben 
Published: April 2024

Abstract

Background/Aims
We carried out a QIP in 2018 as a collaboration between dermatology and rheumatology. 280 patients with psoriasis attending outpatient appointments in dermatology completed Psoriasis Epidemiology Screening Tool (PEST) forms between January and April 2018; results were recorded on the patient record. 110 patients (39%) had a positive PEST score, indicating a possible diagnosis of PsA. Of these, 48/110 were not already known to rheumatology services. Patients with a positive PEST were informed of the results and their GP was advised to refer to rheumatology if they had not previously been assessed. The pathway aimed to avoid duplication of assessments, and acknowledged that patients with psoriasis may have had a rheumatology assessment at another hospital, or even be under their ongoing care.

Methods
We reviewed the hospital electronic and regional patient records of the 48 patients in January 2023 in order to identify which of these had been referred for a rheumatology review and/or had a new diagnosis of psoriatic arthritis.

Results
One patient was excluded due to lack of access to local records. Of the remaining 47 patients, 31 had a PEST score of 3, 15 patients scored 4, and 1 patient scored 5. 5/47 (10%) patients were referred for a rheumatology opinion following a positive PEST score. 3/5 of these patients went on to be diagnosed with psoriatic arthritis. 7/47 (15%) patients had a diagnosis of psoriatic arthritis on GP records with no secondary care input. None of these patients were on treatment for PsA. 7/31 patients with PEST score of 3 were diagnosed with PsA, 2/15 patients with PEST score of 4 and the only patient with a score of 5 were diagnosed with PsA. Overall 10/47 (21%) patients were diagnosed with PsA.

Conclusion
A letter from dermatology to request review of joint disease and consideration of a rheumatology referral in response to a positive PEST score appears to have resulted in a low response in terms of rheumatology review. Others seemingly acquired a diagnosis of PsA without rheumatology review, potentially through the PEST score alone, which is concerning, and not how the PEST score should be used. Screening for PsA in psoriasis populations remains problematic. PEST score is recommended by dermatology guidelines, but lacks specificity and can result in high numbers of referrals, with potential duplication of work if referred repeatedly. It is important to recognise PsA in patients with psoriasis, but equally important that this is done efficiently and accurately, so patients are not inadvertently treated or inaccurately labelled with this diagnosis. Rheumatologists should work with dermatology and primary care colleagues to improve understanding of PsA and the PEST questionnaire, and consider the optimum pathways to ensure that PsA is recognised and treated promptly.

Disclosure
S. Ahmed: None. M. Babiker: None. M. Osama: None. M. Ahmed: None. K. Jobling: None. P. Hampton: None. B. Thompson: None.