[Interstitial lung disease in connective tissue diseases].

Interstitial lung disease represents a major clinical aspect of the four major connective tissue diseases: rheumatoid arthritis, scleroderma, polymyositis/dermatomyositis and systemic lupus erythematosus (SLE). Early recognition in the course of the disease is essential, as interstitial lung disease will often determine the vital prognosis of these patients. Treatment is most frequently based on experts' opinion, because there are only few randomized controlled trials in this field.