Correct Answer: C
Mixed connective tissue disease can be associated with atrophy of the smooth muscle of the gut, like scleroderma. In the esophagus, this can manifest as a hypotensive lower esophageal sphincter and impaired esophageal smooth muscle peristalsis; in extreme cases, there is absent contractility in the esophagus. This contributes to impaired esophageal clearance of refluxed material, leading to prolonged acid residence times in the esophagus and severe reflux esophagitis. Many patients with mixed connective tissue disease have overlap Sjogren’s syndrome, reducing salivary neutralization of esophageal mucosal acidification and further contributing to esophagitis. While esophageal body motor function can be suboptimal in diabetes mellitus and Barrett’s esophagus, the mechanism of hypomotility is not smooth muscle atrophy and fibrosis. Polymyositis can affect skeletal muscle of the proximal esophagus, but not the smooth muscle. Lichen planus affects mucosa but not muscle.
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