Over the course of five days, our four year old presented with some symptoms of diabetes (e.g., lethargy, loss of appetite, fever, urge incontinence, thirst during one night) so her pediatrician did a urine dipstick which showed evidence of glucose but no ketones. However, three hours later, her serum glucose at our regional children’s hospital was 61 mg/dl [3.4 mmol/L], and there was slight presence of ketones (which they believed was due to fasting), but no glucose in her urine. Her HbA1c was 4.4%. How likely is a false positive in her first (pediatrician’s office) urine test? Are there any other organic reasons for glucose in the urine of a child fighting a virus?

There are different methods of testing for urinary sugar. Enzyme strips are generally used a positive reaction is indicative of true glucosuria. Relevant glucosuria is 3+ or 4+. Unexpected reports of “trace” or 1+ or 2+ reaction on routine urinalysis (as I guess happened to your child) may not be significant.

In a four year old child with fever, it is probably meaningless, but you should have your daughter’s urine checked again (when she has recovered) two hours after a high-carbohydrate meal. False positive readings can happen as a result of urine containing high concentrations of certain substances like salicylates (aspirin) and para-aminosalycilic acid (PAS) or if the urine was collected in container washed with ipoclorite or H2O2.

MS