A Case of Pulmonary Embolism in Polymyositis

Polymyositis is an uncommon autoimmune inflammatory myopathy. It is characterized predominantly by proximal muscle weakness with potential involvement of multiple organ systems. Despite ongoing research, its pathogenesis remains incompletely understood. Venous thromboembolism (VTE) is a major health problem, sometimes complicated by pulmonary embolism. Systemic inflammation modulates thrombotic responses by supressing fibrinolysis, upregulating procoagulant, and downregulating anticoagulants. VTE is a multifactorial disease manifesting as either deep vein thrombosis (DVT) or pulmonary embolism (PE). It is the third most common vascular disorder in Western countries, preceding only myocardial infarction and stroke. PE, a serious and potentially fatal condition caused by thrombotic obstruction of the pulmonary arteries, is a rare occurrence in patients with polymyositis. The co-existence of these two conditions represents a clinical entity that warrants further investigation. Autoimmune and immune mediated disorders such as systemic lupus erythematosus, inflammatory bowel disease, polyarteritis nodosa and polymyositis/dermatomyositis have been linked to an increased risk of venous thromboembolism. Chronic inflammatory disorders present with an increased risk of VTE (six to eight times) compared to the general population. The case being presented describes a patient, who was first diagnosed to have pulmonary embolism, followed by a diagnosis of inflammatory myositis due to combination of persistently high creatine kinase levels, radiological findings of inflammatory myositis and abnormal electroencephalogram (EEG). The patient was started on high dose steroid therapy followed by immunosuppressive therapy which led to clinical improvement. It highlights the importance of suspecting venous thromboembolism in cases of inflammatory myositis or other autoimmune conditions.