A puzzling triad: anorexia nervosa, high sweat electrolytes and indication to partial exocrine pancreatic insufficiency.

This report describes a 15-year-old girl with anorexia nervosa whose sweat electrolytes and pancreatic exocrine function were abnormal during a state of malnutrition. Both findings normalized when nutrition improved. The patient did not have any evidence of disorders known to be associated with an abnormal sweat test, including most importantly cystic fibrosis. It is postulated that the elevated sweat electrolytes and the pancreatic insufficiency developed in this patient secondary to malnutrition. The pathophysiological mechanism for both phenomena remains obscure. It is recommended that positive sweat tests in malnourished children should be repeated several times in a corrected nutritional state in order to obviate an erroneous diagnosis of cystic fibrosis.