Idiopathic Pulmonary Hemosiderosis
Idiopathic pulmonary hemosiderosis is a rare disease that causes recurrent diffuse alveolar hemorrhage with no detectable underlying disorder; it occurs mainly in children < 10 years. In patients with idiopathic pulmonary hemosiderosis, repeated alveolar bleeding can eventually result in pulmonary hemosiderosis and fibrosis.
The disease is thought to be due to a defect in the alveolar capillary endothelium, possibly due to autoimmune injury. Many affected patients have celiac disease.
Symptoms and signs of idiopathic pulmonary hemosiderosis in children include recurrent episodes of dyspnea and cough, particularly nonproductive cough initially. Hemoptysis occurs later. Children with idiopathic pulmonary hemosiderosis may present with only failure to thrive and iron deficiency anemia. The most common symptoms in adults are exertional dyspnea and fatigue due to pulmonary hemorrhage and iron deficiency anemia.
Diagnosis of idiopathic pulmonary hemosiderosis involves demonstration of a combination of characteristic clinical findings, iron deficiency anemia, and hemosiderin-laden macrophages in bronchoalveolar lavage (BAL) fluid or lung biopsy specimens plus no evidence of small-vessel vasculitis (pulmonary capillaritis) or another explanatory diagnosis; it is confirmed by lung biopsy if other findings are inconclusive.