Eosinophilic alveolitis in acute respiratory failure. A clinical marker for a non-infectious etiology.

Two patients with acute respiratory failure requiring mechanical ventilation were found to have eosinophilic alveolitis on bronchoalveolar lavage and lung biopsy studies. Neither patient had evidence of lung infection or parasitic disease and both rapidly improved following treatment with corticosteroids. Lung eosinophilia in this setting is unusual, since the stress reaction that accompanies severe illness usually causes a rapid drop in circulating eosinophil levels. Eosinophilic alveolitis in such patients may be a useful clinical marker for non-infectious acute lung injury that is responsive to corticosteroid therapy.