AB0733 PSORIATIC ARTHRITIS IN NIGERIAN PSORIASIS PATIENTS - MYTH OR A MISSING LINK?

Background: Beyond true arthritis, Psoriatic arthritis (PsA) is known with dactylitis and enthesitis. Enthesitis is postulated as the central pathogenic process in seronegative spondyloarthritis1, and the primary finding in psoriatic arthritis2. Psoriasis (and more so PsA) were initially thought to be rare in West Africa. Psoriasis (Ps) is now reported increasingly in Nigeria. But the notion of the rarity of PsA still remains in the absence of systematic documentation of PsA among psoriasis patients, with few cases reported from Rheumatology clinics3. Objectives: This study set out to determine the prevalence of PsA among Nigerian Ps patients using the Classification for Psoriatic Arthritis (CASPAR) criteria, and to evaluate enthesitis amongst them. Methods: This hospital-based, cross-sectional study was carried out at the dermatology clinic over an 18-month period. All patients seen within the study period with biopsy-established Ps were recruited. Fifty-three (53) Ps patients, 16 years or older, were enrolled. The CASPAR criteria was used to diagnose PsA. A modified Spondyloarthritis Research Consortium of Canada (SPARCC) enthesitis chart was used to document entheseal inflammation sites. Diagnosis of enthesitis was made by clinical examination. Results: Fourteen participants fulfilled the CASPAR criteria (8 females, 6 males, F:M = 1.3:1) giving a PsA prevalence of 26.4%. Using the Moll & Wright clinical classification, Oligo/Mono-articular pattern was the most documented (Fig 1). No patient had arthritis mutilans. Enthesitis was found in ALL(100%) PsA patients (Table 1). Highest frequencies were found in the right iliac, right patella and both plantar fascia (Fig 2). Multiple sites were involved in 87.5% of patients. Conclusion: Psoriatic arthritis can not be considered rare among Nigerian Ps patients. Enthesitis has been suggested as the primary finding, and the initial site of inflammation in PsA2,4. Our findings reinforce these theories in an African population. Whilst other studies reported occurence of enthesitis in 30-50% of PsA patients5, our study found 100%. Admittedly though a small study population, it suggests that enthesitis may well be the missing link to finding more PsA patients in Nigeria and Psoriasis patients of West African descent. References: [1]Watad A, Cuthbert RJ, Amital H, Mcgonagle D. Enthesitis : Much More Than Focal Insertion Point Inflammation. Curr Rheumatol Rep. 2018;20:41–8. [2]Barnas JL, Ritchlin CT. Etiology and Pathogenesis of Psoriatic Arthritis. Rheum Dis Clin N Am. 2015;41(4):643–63. [3]Akpabio AA, Olaosebikan BH, Adelowo OO. Psoriatic Arthritis in Nigeria : Case Series and Literature Review. J Clin Rheumatol. 2018;24(4):183–7. [4]Sakkas LI, Alexiou I, Simopoulou T, Vlychou M. Enthesitis in psoriatic arthritis. Semin Arthritis Rheum. 2013;43(3):325–34. Disclosure of Interests: None declared