Pulmonary and gastrointestinal manifestations of Sjögren's syndrome.

The respiratory system is frequently involved in primary SS but this involvement is rarely clinically significant. Its manifestations are secondary to desiccation of the tracheobronchial tree and lymphocytic infiltration of the lung parenchyma. The desiccation of the tracheobronchial tree gives rise to the most important clinical manifestation, dry cough (xerotrachea), but is rarely a cause of infection and obstructive airways disease. The lymphocytic infiltration of the lung parenchyma starts as lymphocytic alveolitis in a very large number of SS patients but rarely evolves into frank lymphocytic interstitial pneumonitis and fibrosis. Even more rare is the evolution of pseudolymphoma into malignant lymphoma. Pleurisy with or without effusion is not a frequent manifestation of primary SS. It occurs often in secondary SS and is due to the underlying rheumatic disorder. In general, secondary SS rarely has significant pulmonary manifestations other than those of the disorder it accompanies. The manifestations from the gastrointestinal system in patients with SS include mucosal dryness, accelerated dental decay, and enlargement of the major salivary glands, as well as dysphagia, nausea, epigastric pain, and dyspepsia. The dysphagia is probably secondary to esophageal dysfunction, and the gastric symptoms might be attributable to chronic atrophic gastritis. Whether the small bowel is affected in SS patients is not clear. Pancreatic involvement usually is being expressed as subclinical acute or chronic pancreatitis. Finally, the liver could be involved in SS patients, and some studies indicate that the pathogenic process responsible for the hepatic damage and for the salivary gland destruction could be similar.