High-altitude pulmonary edema with absent right pulmonary artery.

High-altitude pulmonary edema potentially is fatal. Adults with unilateral absence of a right pulmonary artery are particularly susceptible to high-altitude pulmonary edema. The occurrence of high-altitude pulmonary edema was documented in a child with congenital absence of the right pulmonary artery. Improvement occurred only upon descent to low altitude. Physicians should be aware of this life-threatening condition in children ascending to high altitude, particularly in individuals with unilateral absence of a pulmonary artery.