AB0855 FIBROUS ARTHROPATHY AS THE KEY FEATURE OF JUVENILE SCLERODERMA - CASE REPORT

Abstract

Background:Systemic sclerosis (SSc) is an autoimmune disease characterized by endothelial dysfunction, immunological disorders, and excessive synthesis of collagen and its deposition in various tissues and organs. The juvenile onset SSc before the age of 16 is very rare, with annual incidence of 0.27-0.5 cases per million children according to English and Finnish authors [1,2].Objectives:To present a clinical case of juvenile onset SSc, manifesting from the childhood predominantly with fibrous contractures.Methods:Patient K., 30 yo. Clinical presentation on admission to the Institute of Rheumatology in September 2020: thickening of the trunk and limbs skin (mRSS 10 scores), pronounced induration of subcutaneous tissues and muscles; contractures of the elbow, shoulder, hip and knee joints, short stature (height 142 cm) with proportional shortening of the limbs. ANA (HEp-2) 1/320, a-Scl-70, a-RNP-70 and ACA tests were negative. Ultrasonography revealed left-sided coxitis, esophagogastroduodenoscopy - Barrett’s esophagus. Chest CT, echocardiography, electrocardiography and capillaroscopy yielded no specific findings.The patient has been ill since the age of 3, when SSc manifested with skin thickening, “dry” arthritis and rapid development of contractures of the large joints. Thorough diagnostic elaboration ruled out such potential causes as phenylketonuria, glycogenosis, mucopolysaccharidoses, primary amyloidosis, and porphyria. Histological findings (2007) of a biopsied skin specimen containing subcutaneous fat and muscle tissue included focal vacuolization of keratinocytes, poor perivascular lymphocytic and histiocytic infiltration, fibrosis and hyalinosis of collagen fibers of varying intensity in the in mid- and deep dermis, infiltration of collagen fibers by fibroblasts, skin appendages atrophy – all of them representing a pattern of morphological changes characteristic of SSc. Therapeutic regimens including prednisone at 5-15 mg/day and D-penicillamine were ineffective.Results:In this case, in view of fibrotic arthropathy, a differential diagnosis was made with deep morphea and stiff skin syndrome. Visceral involvement, immunological disorders and biopsy findings substantiated a diagnosis of juvenile onset SSc. Oral MTX was initiated at 15 mg to target skin lesion and osteoarticular symptoms.Conclusion:Predominance of fibrotic arthropathy in presented case caused difficulties in establishing SSc diagnosis, as this patient did not have such inherent features as the Raynaud’s phenomenon, interstitial lung disease or pulmonary hypertension. Juvenile onset SSc manifesting before the age of 16 has its own clinical features, usually persisting through the adulthood, and therefore, such one-of-a-kind appearances of juvenile onset SSc should not be missed or misinterpreted.