Bilateral coxitis in scleroderma-polymyositis overlap syndrome

Abstract

Joint manifestations in scleroderma (Scl) and polymyositis (PM) are dominated by inflammatory arthralgia. Arthritis is less common and preferentially affects the hands, wrists, knees, and ankles. Involvement of the hip has been rarely reported in the literature. We report a case of coxitis diagnosed in a patient suffering from scleroderma-polymyositis overlap syndrome successfully treated by ultrasound-guided infiltration of triamcinolone hexacetonide Key words: Overlap, scleroderma, polymyositis, coxitis, hip involvement IntroductionOverlap syndrome is defined as an entity that satisfies the diagnostic criteria of at least two connective tissue diseases (1). The most common combinations are systemic sclerosis with Sjogren's syndrome, dermatomyositis or polymyositis, rheumatoid arthritis, and systemic lupus erythematosus.Scleroderma is the most frequent connective tissue disorder associated with polymyositis (PM), with a prevalence of around 24% (2). Scleromyositis, a scleroderma/polymyositis (Scl/PM) overlap syndrome, belongs to heterogeneous syndromes of idiopathic inflammatory myopathies, which can be divided into groups on the basis of immunological and clinical features (3). Articular involvement is more frequent in patients where PM is a feature of overlap syndrome, with a prevalence between 25%-42% and preferentially affecting the hands, wrists, knees, and ankles (3, 4). The involvement of the hip is unusual within the connective tissue disease, especially Scl/PM, and has been rarely reported in the literature. Case PresentationA 33-year-old man was followed for 2 years for systemic sclerosis-polymyositis overlap syndrome, retained on clinical (skin sclerosis of the face, fingers and forearms, Raynaud's phenomenon , girdle muscular weakness), biological (positive antinuclear antibodies at 1280 IU/mL, creatine phosphokinase (CPK): 13 times the upper limits of normal, lactate dehydrogenase (LDH): 2.5 times the upper limits of normal, aspartate aminotransferase (AST): 2.5 times the upper limit of normal, alanine aminotransferase (ALT): 1.5 times the upper limits of normal), and histological evidence (muscle biopsy for polymyositis, renal biopsy objectifying focal segmental glomerulosclerosis in favor of scleroderma). The patient was treated with steroids, colchicine, and calcium channel blockers.Two months before his admission, the patient presented with inflammatory pain in the right hip with reduced perimeter of walking (50-100 m). The pain intensity was assessed by the visual analog scale (VAS), which was 9/10. Clinical examination evidenced an antalgic posture with flexion-abduction-external rotation of the right leg, a limp when walking, and restricted motion of both hips, mainly rotations and flexion (flexion 90° in both of hips, internal rotation 10° in the right hip).Radiographs of the pelvis and Lequesne false profile* showed bilateral coxitis with global narrowing, especially of the right hip joint (Figure 1). Magnetic resonance imaging (MRI) of the pelvis showed bilateral synovitis more im...