An investigation has been conducted into cases of acute idiopathic pulmonary hemorrhage among infants in Massachusetts from December 2002 to June 2003. The condition appears to be related to various respiratory issues affecting infants, including pulmonary hemorrhage, interstitial lung disease, and respiratory distress syndrome. The exact cause of the condition is unclear, with possible correlations to food allergy, pulmonary artery thromboembolism, and other factors being explored.