Joint contractures responsive to immunosuppressive therapy in a girl with childhood‐onset systemic sclerosis double‐seropositive for rare anti‐nucleolar autoantibodies: a case report

BACKGROUND: Systemic sclerosis (SSc; scleroderma) is an autoimmune connective tissue disease that affects the skin and subcutaneous tissue, in addition to the internal organs of the whole body. Onset in childhood is uncommon; however, both patients with childhood-onset and adult-onset SSc are positive for anti-nuclear antibodies (ANAs).Detection of SSc-related anti-nuclear antibodies is often useful for predicting clinical features, disease course, and outcomes. CASE PRESENTATION: A 5-year-old Japanese female manifested gradually progressive abnormal gait disturbance, regression of motor development, Raynaud’s phenomenon, and the shiny appearance of the skin of the face and extremities at age 2. On admission, she presented a mask-like appearance, loss of wrinkles and skin folds, puffy fingers, moderate diffuse scleroderma (18/51 of the modified Rodnan total skin thickness score), and contracture in the ankle and proximal interphalangeal joints. Grossly visible capillary hemorrhage on nail fold and severe abnormal capillaroscopy findings including bleeding, giant loop and disappearance of capillaryconsistent with the late phase in SSc. A skin biopsy showed fibrous thickening of the dermis, entrapment of an eccrine sweat glands, and thickened fiber. Chest high-resolution computed tomographic scanning demonstrated patchy areas of ill-defined air-space opacity and consolidation predominantly involving the posterior basilar aspects of the lower lobes presenting withinterstitial lung disease. Positive ANA (1:160 nucleolar and homogeneous nuclear staining by indirect fluorescent antibody technique) and double-seropositive for anti-Th/To and anti-PM-Scl antibodies were identified. She was diagnosed with diffuse cutaneous SSc based on the Pediatric Rheumatology European Society/American College of Rheumatology/European League Against Rheumatism Provisional Classification Criteria for Juvenile Systemic Sclerosis and was successfully treated with immunosuppressive agents, including methylprednisolone pulses and intravenous cyclophosphamide. CONCLUSIONS: We experienced the first case of juvenile SSc with anti-PM-Scl and anti-Th/To antibodies. ILD was identified as a typical feature of patients with these autoantibodies; however, diffuse cutaneous SSc and joint contraction were uncharacteristically associated. The case showed unexpected clinical findings though the existence of SSc-related autoantibodies aids in determining possible organ involvement and to estimate the children’s outcome.