Scleroderma is a rare disease in which a person's immune system begins to destroy normal, healthy tissues (autoimmune disease). As a result, connective tissue of the skin, lungs, and internal organs—especially the esophagus, kidneys, and digestive tract—is replaced with scar tissue. This change causes the tissues to become stiff and the muscles to not work as well.

In the esophagus, this makes it:

• Easier for stomach juice to get into the esophagus, because the valve between the esophagus and stomach (lower esophageal sphincter) does not close tightly.
• Harder to move stomach juices out of the esophagus because the squeezing motion of the esophagus (peristalsis) does not work as strongly.