Sir.—In response to the report by Keating and associates1 in the September 1991 issue of AJDC documenting the recent increases in the incidence of water intoxication in infants and the resurgence of interest in this increasingly common syndrome in US inner cities,2-4 a retrospective records review was performed at The Johns Hopkins Hospital, Baltimore, Md, looking for cases of water intoxication. Our findings confirm the observation of Keating et al that water intoxication, a previously rare condition, is increasing in frequency. The cases at The Johns Hopkins Hospital differ, however, in the reasons given by parents for feeding infants excessive free water.
A search was performed by The Johns Hopkins medical record computer system for cases of hyponatremia as either the principal or one of four secondary diagnoses for patients aged newborn to 6 years during an 11½-year period from January 1979 through June 1990. A total