A 14-year-old girl with early-onset inclusion body myositis, systemic lupus erythematosus, Sjögren's syndrome, and autoimmune thyroiditis: a case report and literature review

Abstract

Abstract Background: Sporadic inclusion body myositis is predominantly affecting the elderly population. It is insidious and easily misdiagnosed as other forms of neuromuscular and inflammatory myopathy. Patients may be treated with steroids and immunosuppressants for many years, leading to severe side effects. A correct diagnosis will also help avoid using high doses of steroids and immunosuppressants. Case Presentation: We report a case of a 14-year-old girl diagnosed with sporadic inclusion body myositis, Sjögren's syndrome, systemic lupus erythematosus, and autoimmune thyroiditis. She was treated with steroids, intravenous immunoglobulin, and rituximab, which failed to relieve the progressive muscle weakness. Considering previous published cases, this case may be classified as a rare early onset form. Conclusions: Our patient had a family history of autoimmune thyroiditis combined with various connective tissue diseases. The persistence of thyroid autoantibodies may have predicted the onset and diagnosis of sIBM. In this case report, overlapping immune diagnoses and unusually young age may be factors in misdiagnosis of sporadic inclusion body myositis. Early and more positive treatment should be a discussion of future research. We suggest that failed treatment may be related to the patient's muscle enzyme levels.