October 25, 2006
Diagnosis and Symptoms
Question from Chilton, Wisconsin, USA:
My daughter was sick recently, fever, vomiting, chills, and sore throat. I took her to the doctor thinking she had strep throat or something similar. While there, I mentioned that she has been very thirsty lately (getting up five times a night before with complaints of thirst) and tired at odd times, complaining of being tired on the way to preschool, etc. The doctor did a urine test and found ketones, sugar, and blood in her urine. They then did a finger prick blood test and her blood sugar was 249 mg/dl [13.8 mmol/L]. We were then sent to a pediatrician for a follow-up. They repeated the urine test with the same results. A venous blood test, however, came back normal. The first fingerprick test was approximately two hours after eating and the second test was approximately four hours after eating. They took more blood and are doing an A1c test and we go back for those results tomorrow. Could the first blood test have given a false reading? Is there another explanation for the sugar in her urine other than diabetes? Does the fact that her blood sugar when down on its own mean she does not have diabetes?
Given her symptoms and laboratory testing, your daughter clearly may have diabetes. I would recommend close follow-up with your pediatrician who can help to direct any testing that may be necessary to rule in or rule out the diagnosis of diabetes. Although fingerstick blood sugars are usually quite accurate, it is important not to base a diagnosis of diabetes on a handheld glucometer result. It is more accurate to have a confirmatory laboratory run blood test. The vast majority of kids that have sugar in their urine have diabetes. There are some other very rare causes of sugar in the urine. A normal blood test for sugar does not rule out the diagnosis of diabetes — further testing clearly may be indicated.