Onset of Psoriatic Arthritis at the Hip Joint Without Spondylitis

Abstract

Psoriatic arthritis (PsA) is an inflammatory arthritis associated with psoriasis that may have an indolent or progressive course. Several factors can contribute to delay in diagnosis of PsA, including insidious onset, lack of symptoms, and absence of a specific diagnostic biomarker (1). The diagnosis of PsA is based on clinical evaluation and imaging, and may be difficult in patients with coexisting osteoarthritis, even for rheumatologists (2). We describe here a rare case of PsA with hip joint involvement at onset. Inflammatory hip joint disease occurs in less than 10% of PsA patients, and involvement of the hip joint at onset is rare (3). In this case, inflammatory disease of the hip joints developed at a relatively young age with radiological evidence of erosion and ankylosis, requiring bilateral hip arthroplasty. Despite oral methotrexate treatment after left hip arthroplasty, computerized tomography revealed asymptomatic sacroiliitis. We suggest that psoriatic hip arthropathy may require early treatment with methotrexate or leflunomide along with intra-articular steroid injections, following anti-tumour necrosis factor alpha (anti-TNFα) therapy.