ESSENTIAL fructosuria, apparently a harmless condition, is an extremely rare error of metabolism, the recognition of which is of importance because it may be mistaken for diabetes mellitus. It is characterized by the patient's inability to utilize fructose normally, whether it is ingested as simple fructose or as a substance capable of yielding fructose on digestion, such as cane sugar. It is manifest clinically by a symptomless excretion of fructose in the urine.
The infrequency of the condition seems to justify the report of 2 cases. In 1942, Sachs, Sternfield and Kraus1 reviewed 55 cases in the literature, 39 of which fulfilled the criteria for essential fructosuria. In this series, the ages of the patients ranged from 2½ to 87 years, with representation in all decades. The condition has been seen in a father and 2 daughters and in sets of 2 and 3 siblings. Lasker2 supplied evidence