Idiopathic pulmonary hemosiderosis (IPH) is an uncommon disorder of unknown etiology. It manifests as a triad of hemoptysis, diffuse intra-alveolar infiltrates on chest radiograph (CXR) and iron deficiency anemia. Although the association with cow’s milk protein allergy and celiac disease has been reported in some patients, the etiology of repeated pulmonary hemorrhage in IPH remains unknown.
A 3-1/2 year-old girl with an episode of profound iron deficiency anemia (hemoglobin [Hb] 3.4gm/dL, hematocrit [Hct] 12.1%) at 1-1/2 years of age, received packed red blood cells (PRBC), currently presented with symptoms of upper respiratory infection, cough and fever. In the emergency department, she had temperature 100.7 F, pulse 178 /min, respiratory rate 68 /min, BP 87/52, and oxygen saturation of 80% on room air. She was pale, lethargic, had moderate intercostal retractions and clear lung sounds with good air entry. Arterial blood gas was pH 7.42, PaCO2 32mmHg, and PaO2 75mmHg on 2 L/min of oxygen via facemask. CBC showed Hb 4.8 gm/dL, Hct 15.2%, MCV 60, WBC 13.8 k/cumm and reticulocyte count of 6.6 %. CXR showed bilateral diffuse fluffy infiltrates (Fig. 1). She was admitted to the pediatric intensive care unit, given oxygen and transfused with PRBC. Computerized tomography (CT) of the chest showed a diffuse airspace disease (Fig.2). Bronchoscopy with bronchoalveolar lavage (BAL) was followed by an open lung biopsy. Both showed hemosiderin-laden macrophages. Biopsy showed acute and chronic intra-alveolar hemorrhage and strongly positive stain for iron (Fig.3, 4). Bacterial, viral, fungal and acid-fast smear and culture were all negative as was the stain for pneumocystis carinii. Work-ups for rheumatologic diseases, hypersensitivity pneumonitis, celiac disease and bleeding disorders were negative. Stachybotris chartarum IgE and IgG were within normal limits and anti-cow’s milk proteins IgG was absent. IgE was elevated at 2290 u/mL. She was treated with intravenous methylprednisolone 2 mg/kg/day with improvement. Upon discharge from hospital, Hb and Hct were 13.9mg/dL and 42.7% respectively and CXR showed resolution of alveolar infiltrates. The prednisolone dose was tapered off over a 4-months period when Hb decreased to 10.6 gm/dL. She appeared pale but had no hemoptysis. A CXR revealed prominent interstitial markings. High resolution CT (HRCT) of the chest showed a fine nodular pattern throughout the lung fields. She was then started on azathioprine 4 mg/kg/day and has done well since then.DISCUSSION: The prognosis of IPH is difficult to predict because of paucity of the reported data. Death may occur suddenly from an acute pulmonary hemorrhage or from chronic respiratory failure secondary to pulmonary fibrosis. Survival varies among the reported series from 2.5 years to 86% 5 years survival rate. Efficacy of the treatment is also difficult to assess due to the variable clinical course and rarity of the disease. Corticosteroids (CS) are most commonly used. However, the disease can progress even while the patient is on it. Other immunosuppressants are occasionally employed for those who have poor response to CS. Lung transplantation has been reported in one patient with unsuccessful outcome.
IPH may present atypically in children who do not have a history of hemoptysis because they swallow sputum. IPH is a diagnosis of exclusion. The diagnosis is considered in the presence of hemosiderin-laden macrophages in BAL and in the lung biopsy specimen when other common causes of hemorrhage are excluded. The lung biopsy should not show any evidence of vasculitis, capillaritis, granulomas or immunoglobulin deposition. CS and other immunosuppressants are used in acute episode and for chronic maintenance therapy but the response is variable. A diagnosis of IPH should be considered for a patient with intermittent dyspnea, pulmonary infiltrates and iron deficiency anemia.
D. Vaysman, None.