Idiopathic neonatal eosinophilic pneumonia is extremely rare. We report an
infant who presented with tachypnea and interstitial infiltrates on chest r
adiograph at age 2 wk. Lung biopsy revealed perivascular and interstitial e
osinophils. Despite initial improvement, the patient's condition became res
istant to corticosteroids, cromolyn, and intravenous gamma globulin. After
treatment with cyclosporin A his symptoms resolved.