Systemic lupus erythematosus, eosinophilia and Löffler's endocarditis. An unusual association.

A 24-yr-old male, known since the age of 11 to have a nonerosive arthritis and later diagnosed as having systemic lupus erythematosus (SLE), developed subacute heart failure with diffuse lung infiltrates and died suddenly after having presented a moderate hypereosinophilia for 6 months for which no other causes besides the SLE were found. A post mortem examination revealed Löffler's endocarditis (endocarditis parietalis fibroplastica) with acute pulmonary capillaritis. This represents Löffler's endocarditis in the setting of SLE. To the best of the authors' knowledge, this association has not been reported before.