Reversible pulmonary arterial hypertension in a 6-year-old girl with extrinsic allergic alveolitis.

A case is reported of a 6-year-old girl who developed extrinsic allergic alveolitis due to hypersensitivity to her pet budgerigars. Pulmonary artery pressure measurements obtained by a cardiac catheterization demonstrated a significant increase in the pulmonary vascular resistance during the acute stage of the disease. Six months after exclusion of exposure to the budgerigars the hemodynamic of the pulmonary circulation was normalized. The present case thus shows that a reversible increase in the pulmonary vascular resistance in extrinsic allergic alveolitis of childhood may occur without development of an irreversible pulmonary fibrosis.