The article by Tejani et al in this issue (p 1000) makes two important points about hypernatremic dehydration. The first has to do with its incidence expressed as a proportion of all dehydrated infants admitted to the hospital for dehydration secondary to enteritis over a certain period. From 1950 to 1970, various reports from the United States and similar countries gave percentages varying from 9% to 68% for particular periods.1 During that era, corresponding incidences of hypernatremia in developing countries were much lower. We speculated that malnutrition with its low body-water tonicity and low-solute diets were factors. Hypernatremic dehydration was one more adverse consequence of a technologically advanced, affluent industrial society.
Our speculations were probably correct. As formula feeding has moved to underdeveloped areas, reports from these areas have shown an increase in the frequency of hypernatremia since 1970.1,2 As lower-solute feedings—no more home-prepared dry-milk feedings in Great
FINBERG L. Dehydration and Osmolality. Am J Dis Child. 1981;135(11):997-998. doi:10.1001/archpedi.1981.02130350001001