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Diagnosing acute onset diabetes in a child

Paediatric endocrinologist Professor Timothy Barrett advises on the key signs and pitfalls in diagnosing type 1 diabetes in children

Paediatric endocrinologist Professor Timothy Barrett advises on the key signs and pitfalls in diagnosing type 1 diabetes in children

Worst outcomes if missed

• Death – mortality in type 1 diabetes is usually due to complications of diabetic ketoacidosis (DKA), notably cerebral oedema. Up to 40% of children present with DKA, and mortality has been reported as 0.7%.

• Diabetic coma – this occurs in 25% of older children and up to 40% of under-fives at diagnosis. Children can rapidly deteriorate with reduced consciousness, coma and death.

• Cerebral oedema – this is usually preceded by DKA, and may present with the classic signs of raised intracranial pressure – bradycardia, hypertension, reduced consciousness.

The key message is to refer a child the same day to secondary care if a diagnosis of diabetes is suspected.


Type 1 diabetes is hyperglycaemia secondary to absolute insulin deficiency, due to autoimmune destruction of the pancreatic beta cells.

It affects about 1 in 300 UK children and its prevalence is increasing, so that it is now one of the commonest chronic diseases in childhood.

The fastest increase in incidence is in the under-fives, where it can present suddenly with symptoms presenting in less than six hours.

There are two peak ages of presentation: under five years and 14-18 years. Children who present younger tend to have more acute symptoms.

There is a clear seasonal incidence reported, with more cases presenting in the winter and spring months, but there is some evidence now that presentations are more evenly distributed throughout the year.

Symptoms and signs

Children usually present with a short history – days or weeks – of weight loss, lethargy, thirst and polyuria. There are several symptoms more commonly seen in children than in adults including:

• sudden onset of bedwetting after being dry at night

• general lack of energy

• poor school performance.

In addition, like adults, affected children get up at night to go to the toilet and for a drink, report drinking litres of fluid a day, and may report being excessively hungry. Occasionally, families report a preceding viral infection.

Findings on examination may include:

• evidence of recent weight loss – loose skin folds on the arms

• signs of dehydration

• vaginal thrush or balanitis

• urinary tract infection.

Signs of dehydration to look out for include:

• reduced skin turgor – when the skin on the back of the hand does not immediately spring back into place after being pinched

• sunken eyes

• dry mucous membranes.

In severe cases, the child may have a smell of ketones on the breath – smelling like pear drops or acetone. The key test is a capillary blood or urine sample

for glucose. If raised, this is effectively diagnostic of diabetes.

Differential diagnosis

• Non-specific viral illness. This is the commonest misdiagnosis, as many symptoms of diabetes may be non-specific in the early stages. Ask about increasing thirst, which is uncommon with viral illness alone. Every child who presents with increasing thirst and a viral infection should have urine checked for glucose.

• Type 2 diabetes. Unfortunately this has emerged in the child population in the past ten years associated with the rising prevalence of childhood obesity. Type 2 diabetes is hyperglycaemia secondary to tissue insulin resistance with a relative, not absolute, insulin deficiency. Children tend to be obese, with no history of weight loss, present in puberty (12-16 years), and often with a family history of type 2 diabetes in one or more parents or grandparents. These children also need same-day referral to secondary care as there can be diagnostic confusion with type 1 diabetes and because of the risk of hyperosmolar non-ketotic coma, also seen in these children.

First-line investigations

41213582Any child with suspected diabetes, whether type 1 or type 2, should have their urine or capillary blood checked for glucose. Any reduction in consciousness or evidence of dehydration should prompt immediate transfer to hospital. The presence of any glucose in the urine, or a random capillary blood glucose greater then 11mmol/l, should prompt the same-day referral to secondary care. Poorer outcomes have been related to delay in referrals.

Second-line investigations

41213581These include:

• assessment of consciousness (Glasgow Coma Score or its paediatric equivalent)

• assessment of dehydration

• capillary blood gas

• venous sample for serum electrolytes and glucose.

Further investigations will be dictated by the initial findings, but may include neuroimaging for cerebral oedema.

Professor Timothy Barrett is professor of paediatric endocrinology at The Children's Hospital NHS Trust, Birmingham

Competing interests: none declared

Herrings Key Extreme thirst and dehyadration are common symptoms Extreme thirst and dehyadration are common symptoms

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