mixed connective tissue disease (MCTD), a systemic disease characterized by the combined symptoms of various collagen diseases, such as synovitis, polymyositis, scleroderma, and systemic lupus erythematosus, with a high concentration of antibodies of ribonucleoprotein. Other symptoms may include arthralgia, muscle inflammation, nondeforming arthritis, swollen hands, esophageal hypomotility, and reduced diffusing capacity of the lungs. Treatment often includes the administration of corticosteroids. Recurrence is common when the steroid medication is discontinued.
