Shrinking lung syndrome in systemic lupus erythematosus. A report of three cases.

Shrinking lung syndrome of systemic lupus erythematosus is characterized by dyspnea, diaphragmatic elevation with decreased mobility, and a restrictive defect. We report three cases in females with systemic lupus erythematosus aged 25, 29, and 42 years. Dyspnea and chest pain were present in all three patients. Elevation of the diaphragm was bilateral in two patients and unilateral in one. Two patients had a very severe restrictive defect. Onset of the pulmonary manifestations occurred in the absence of a flare of the connective tissue disease in two patients. Corticosteroid therapy consistently produced a clinical improvement with a decrease in the restrictive defect. Evidence suggesting diaphragmatic dysfunction is discussed.