Cystic fibrosis with acute hypoelectrolytemia and metabolic alkalosis in infancy.

We describe two infants with previously undiagnosed cystic fibrosis who had electrolyte 
depletion, metabolic alkalosis, and dehydration in the winter and three infants 
known to have CF in whom similar manifestations developed. We confirm 
previous reports that salt depletion and metabolic alkalosis do occur throughout 
the year in the northern United States and England. When metabolic 
alkalosis and hypoelectrolytemia in infancy are not explained on the basis 
of other clinical conditions, CF should be suspected. Pediatricians should measure 
serum electrolyte values promptly and consider early parenteral fluid and electrolyte 
therapy as a preventive measure for infants with CF with persistent 
vomiting and/or diarrhea. 