Coexistence of Systemic Lupus Erythematosus and Myasthenia Gravis: An Unusual Case of Polyautoimmunity. / Coexistencia de lupus eritematoso sistémico y miastenia gravis. Una expresión infrecuente de poliautoinmunidad.

The relevance of polyautoimmunity, defined as the presence of 2or more autoimmune diseases in the same individual, is one of the issues not yet elucidated in medical practice. The coexistence of myasthenia gravis (MG) and systemic lupus erythematosus (SLE) is a clinical challenge due to the possible differential diagnoses of muscle involvement in patients with SLE. We present the case of a patient who came to the emergency room of Hospital Universitario San Ignacio in Bogotá, Colombia, with a previous diagnosis of SLE, who developed acute weakness in the context of a systemic infection, with a clinical and electrophysiological diagnosis of MG.