Purpose of review: In this review we discuss the changing concepts of diffuse alveolar hemorrhage in children in terms of an expanded differential diagnosis and new approaches to diagnosis and treatment.
Recent findings: More commonly found in adults, pulmonary capillaritis, an immune-mediated form of diffuse alveolar hemorrhage often associated with systemic disease, has been recently reported in children. In a series of eight children with pulmonary capillaritis, serology for immune-mediated disorders was positive in only half. Acute idiopathic pulmonary hemorrhage is a unique condition of infants who present with acute pulmonary hemorrhage and respiratory failure. The hypothesis that acute idiopathic pulmonary hemorrhage is caused by toxigenic mold has not been proven, and its cause remains uncertain.
Summary: Classification of diffuse alveolar hemorrhage in children has been revised to include those conditions with and without pulmonary capillaritis. As idiopathic pulmonary hemosiderosis, the classic form of diffuse alveolar hemorrhage in children, is a diagnosis of exclusion and children with pulmonary capillaritis may have negative serology, lung biopsy should be strongly considered in any child with diffuse alveolar hemorrhage without a cardiovascular cause. Generally, patients with immune-mediated lung disease require more aggressive pharmacologic intervention.