A variety of radiographic findings have been described in patients with pulmonary hemosiderosis. Mild, transient infiltrates are the only abnormalities in some cases, while extensive perihilar infiltrates may be noted in others. The findings may be mistaken for pulmonary edema. A reticulonodular appearance suggestive of interstitial fibrosis is often noted in the lower lobes in cases of resolving hemorrhage. Laboratory findings at presentation typically include a hypochromic, microcytic anemia.
Most patients demonstrate a reticulocytosis during periods of acute pulmonary hemorrhage.
A positive direct Coombs test and cold agglutinins are sometimes noted. Leukocytosis and an elevated erythrocyte sedimentation rate not uncommonly accompany episodes of pulmonary hemorrhage. Children with cow's milk sensitivity may have elevated levels of serum antibodies to constituents of cow's milk or positive intradermal skin tests to cow's milk proteins. Stool guaiac evaluation is frequently positive because of swallowed pulmonary blood. Pulmonary function tests may demonstrate abnormalities including poor compliance and airway obstruction.