Trophic ulcers are common, especially on the fingertips, overlying the finger joints, or over calcinotic nodules. Acid reflux resulting from lower esophageal sphincter incompetence, and peptic esophagitis with possible ulceration and stricture are common. Hypomotility of the small intestine may be associated with malabsorption resulting from anaerobic bacterial overgrowth. Pneumatosis cystoides intestinalis may follow degeneration of the muscularis mucosa and entry of air into the submucosa of the intestinal wall. Characteristic large-mouthed sacculations can develop in the colon and ileum because of atrophy of the smooth muscle of these segments.
Lung fibrosis causes early impairment in gas exchange leading to exertional dyspnea.
Pleurisy and pericarditis with effusion may occur. Lung involvement generally progresses indolently, with substantial individual variability. Cardiac arrhythmias, conduction disturbances, and other ECG abnormalities are common. Heart failure may develop because of pulmonary hypertension and secondary cor pulmonale or because of diffuse fibrous replacement of cardiac muscle. Heart failure tends to be chronic and difficult to treat.