521 - A Case of Overlapping Connective Tissue Disease: Polymyositis + Systemic Scleroderma

Case Diagnosis: Polymyositis with overlapping systemic scleroderma

Case Description: A 46-year-old female with a history of mixed connective tissue disease presented with progressive global muscle weakness for seven months following a flu-like illness. She also reported dysphagia, dyspnea, 30lb weight loss, skin rash, dry mouth, and dry eyes. Upon clinical presentation, there was bilateral deltoid and quadriceps atrophy, telangiectasias on her face and chest, hyperpigmentation of the right forearm, livedo reticularis on bilateral arms, and puffy digits. Exam demonstrated limited neck flexion with truncal and extremity weakness. Laboratory testing showed positive ANA 1:1280, positive anti-PM/SSc, anti-RNP 2.0, rheumatoid factor 26.9, elevated liver function tests, and creatine kinase 1213. A muscle biopsy and EMG were consistent with myositis. Echocardiogram demonstrated a dilated inferior vena cava. Treatment was initiated with intravenous immunoglobulin (IVIG) infusions and oral methotrexate. Methotrexate was discontinued (rash) in favor of mycophenolate mofetil/Cellcept®. Her symptoms improved. One year later, she developed interstitial lung disease managed by mycophenolate mofetil/Cellcept®.

Discussions: This study describes a rare case of overlapping polymyositis and systemic scleroderma that was confirmed with laboratory testing, muscle biopsy, EMG, cardiac and dermatology evaluation. It is not fully understood what triggers autoimmune diseases, but viruses are believed to be a potential cause. This supports the patient’s rapid decline after her illness. Monitoring heart and lung function is encouraged with this diagnosis.

Conclusions: Polymyositis with overlapping scleroderma is a rare condition with significant morbidity. Consistent with autoimmune disorders, symptom presentation may vary among patients. Better understanding of this diagnosis by recognizing different case presentations, will expand our knowledge of the condition. As a result, we can identify the condition(s) sooner, implement targeted and effective treatments, and help counsel patients about their diagnosis.