Dermatomyositis: A Rare but Deadly Cause of Dysphagia

Abstract

Background: Dermatomyositis is part of a subgroup of inflammatory myopathies that includes polymyositis and inclusion-body myositis. Dermatomyositis is distinguished by its clinical features including pathognomonic rash with associated proximal muscle weakness. Dysphagia is a common but potentially life-threatening of dermatomyositis and can be present in up to 60% of cases. We report two cases of patients who developed moderate to severe dysphagia secondary to dermatomyositis treated with intravenous immune globulin (IVIG). Case Series: Patients with known dermatomyositis presented with acute oropharyngeal dysphagia. The first patient was a 28-year-old female who presented 2 weeks after being diagnosed with dermatomyositis with worsening oropharyngeal dysphagia. The second patient was an 80-year-old male with a 3-month history of dermatomyositis who presented with a 1-month history of progressively worsening oropharyngeal dysphagia. Both patients were ruled out for an acute upper pharyngeal obstruction with imaging of the neck and ENT evaluation. They each received highdose systemic corticosteroid and methotrexate but were refractory to treatment. This prompted the use of intravenous immune globulin (IVIG) for each. One patient had complete resolution of dysphagia 1 week after administration of IVIG and the other patient continued to have dysphagia ultimately requiring PEG tube placement. Discussion: Dermatomyositis is a complement-mediated intramuscular microangiopathy that affects skin and muscle. The complement membranolytic attack complex deposits into the capillaries which leads to skeletal muscle ischemia and muscle fiber necrosis. This process can affect the upper third of esophagus resulting in dysphagia which is associated with a 1-year mortality rate of 31%. Patients who cannot protect their airway are at increased risk of developing aspiration pneumonia which is the leading cause of death among this group. The mechanism of IVIG, though not entirely understood, works by blocking the Fc receptors on the vascular wall thus preventing and competing with the membrane attack complex deposits from entering endomysial capillaries. Although various studies have used a combination of therapies that include prednisone, methotrexate, azathioprine, cyclophophamide, or cyclosporine, many patients become resistant to all therapies. IVIG is then used with varying results. Conclusion: We present two cases of dermatomyositis complicated by dysphagia that was promptly treated with IVIG. Response to IVIG is variable which is consistent with previous studies. However, once dysphagia occurs, treatment options are limited and thus IVIG therapy should be instituted.