Diabetes in children Heed the early warning signs to prevent a delay in diagnosis and treatment BY Heather J. Dean, MD and Elizabeth A.C. Sellers, MD

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The diagnosis of diabetes in a child is simple when the random plasma glucose (RPG) is >/- 11.1 mmol/L. Classifying the type of diabetes in children, however, can be challenging with the recent description of early-onset type 2 diabetes and the discovery of single gene disorders that cause defects in insulin secretion. Only a few years ago, all diabetic children were thought to have autoimmune type 1 diabetes. The development of type 2 diabetes in children has raised concern about the potential delay in diagnosing the life-threatening type 1 diabetes. Because physicians are dealing with an explosion of type 2 diabetes cases in adults, they may not recognize the urgency of diagnosis and referral of a child with type 1 diabetes. This article will guide the primary care physician in this diagnostic dilemma, and encourage immediate consultation with a specialized multidisciplinary pediatric diabetes team for a child with diabetes, regardless of the type.

How do I diagnose diabetes in a child?
When a child of any age presents with symptoms of polyuria and polydipsia, the physician must initially consider a diagnosis of type 1 diabetes. The symptoms, usually of acute onset and lasting only 1-2 weeks, may be accompanied by weight loss, fatigue or enuresis. Despite these symptoms, many clinicians have been fooled by how well these children appear. Moreover, the presentation in children younger than three years of age is even more difficult as the only signs they may show are irritability and soaked diapers. In these cases, the physician has to be very astute. Children with diabetic ketoacidosis (DKA) on presentation will look ill, with abdominal pain and vomiting being two of the cardinal symptoms. The telltale sign of DKA is dehydration with copious urine output.

On presentation, many children will have small to large ketones in the urine. This indicates ketonemia and ketonuria, but not usually DKA. The latter can only be confirmed with a capillary blood gas (pH < 7.35 and HCO₃ < 15) or by a low total venous CO₂ (if gases aren't available).

It's imperative to request an immediate random venous plasma glucose (RPG) to confirm the diagnosis of diabetes. If a stat RPG isn't available, a capillary random blood glucose (RBG) using a glucose machine in the office, or a urine dipstick, will give highly specific results. Any RPG >/- 11.1 mmol/L or glucosuria in a child indicates the need for immediate telephone referral to a pediatric centre with experience treating diabetes in children. Waiting for a fasting blood glucose result can mean a serious and dangerous delay in diagnosis and treatment of a symptomatic child.

How is treatment different in children?
The diagnosis of a serious life-threatening chronic disease in a child is associated with profound challenges for parents and siblings. For this reason, regional single-site multidisciplinary pediatric diabetes teams exist in every Canadian province to provide family centred specialized diabetes care in partnership with the family physician. Other major challenges in children are the complex developmental stages and school safety. The potential insulin regimes are the same in children as in adults. Children of all ages can use intensive diabetes management, including continuous insulin infusion by pump. The decision of the optimum insulin regime is best decided by a thorough discussion between the diabetes educators, physician and the family.

Compared to adults, there are major differences when managing DKA in children. The mortality in children associated with DKA is due to cerebral edema, a complication that rarely occurs in adults. Although the cause of cerebral edema remains controversial, treatment guidelines are constructed to limit the risk of this complication in children. The general principles for children include: slow rehydration, no bicarbonate, no insulin bolus, adequate potassium replacement and intensive metabolic and neurologic monitoring. This must always be done in consultation with a centre experienced in managing DKA in children. A recent edition of Canadian Diabetes, published by the Canadian Diabetes Association, featured an article on how to handle DKA in children, and was sent to all family physicians in Canada.