Recurrent Metabolic Alkalosis in a Cystic Fibrosis Patient: Coexistence with Congenital Chloride Diarrhea

Metabolic alkalosis is uncommon in infancy. Cystic fibrosis (CF) patients can develop dehydration because of sweat salt or gastrointestinal losses; with the correct salt supplementation, the electrolyte alterations can be reversed. Here, we present a CF patient with recurrent metabolic alkalosis, initially oriented as pseudo-Bartter's syndrome. However, despite accurate treatment, patient needed daily intravenous fluids to maintain homeostasis. An extended study was made, including a urine study that could rule out Bartter's diagnosis. Finally, after a complementary test that included electrolyte stools study and genetic analysis, congenital chloride diarrhea could be diagnosed.