Hypoelectrolytemia as a presentation and complication of cystic fibrosis.

We describe three patients with cystic fibrosis (CF) with four episodes of hypoelectrolytemia, two of which were associated with documented metabolic alkalosis. CF should be included in the differential diagnosis of infants and children presenting with hypoelectrolytemia and metabolic alkalosis. Patients with CF are at risk of developing severe hypochloremia in hot weather and during intercurrent illness. An abrupt diminution of oral intake is an important suggestive sign, alerting the physician to look for the development of hypoelectrolytemia.