A 13-year-old boy presents to your rural GP practice with a sore throat, abdominal pain and general malaise. You note he is tachypnoeic. His mother mentions some weight loss over the past two weeks though she had not been concerned about this because his weight was >95th centile and BMI >98th centile.
You prescribe amoxicillin but he re-presents the next day with his mother. After being asked directly, his mother recalls her son has had polyuria and polydipsia for a few weeks. A finger prick blood glucose level (BGL) reads ‘high’. A finger prick ketone level is 5.5. He is not his normal self, with breathing observed to be deep, rapid, and laboured. You send him to the emergency department.
On arrival at the regional ED, he is drowsy and confused, with GCS 13-15, pulse 130 bpm, and normotensive. Skin perfusion is slow at 3.5 seconds and his blood gas is: pH 6.85, PCO2 19, Bicarb 3, BE -30, Na 123, K+4.2, glucose 38, ketones 7.
He is transferred via Royal Flying Doctor Service to a paediatric tertiary referral intensive care unit, treated with an IV insulin infusion and IV fluids according to the local diabetic ketoacidosis (DKA) protocol. Once his acidosis normalises, the boy is transitioned to subcutaneous insulin and – while in hospital with his family – educated about type 1 diabetes (T1D).
How many children have T1D, and how many have DKA at diagnosis?
Over recent decades there has been a well-documented increase in the incidence of T1DM in WA, Australia, Europe and the USA. In WA the prevalence of moderate to severe DKA at the time of diagnosis has also increased. A recent WA-based study identified 2111 children diagnosed with T1DM <16 years of age over a 20-year period. Moderate-severe DKA at diagnosis occurred in 25.3% of this group and may be associated with a more adverse long-term trajectory for glycaemic control.
When might DKA be more difficult to diagnose?
Most clinicians can identify a classical history of T1DM in a school-aged child, presenting with polyuria, polydipsia, weight loss and hyperphagia. In Europe, public health campaigns focusing on new onset enuresis in previously dry children – a more subtle sign of T1DM – are having success in preventing DKA.
Children <5 years of age, who may be variably toilet trained and in whom symptoms may be less clear or more difficult to distinguish from common early childhood illness, are a more challenging group to diagnose. Consider T1D in a young child with increasing lethargy, weight loss (or poor weight gain), or increasing frequency or heaviness of wet nappies.
Another diagnostic conundrum is differentiating between T1DM and T2DM. Australian youth have high rates of obesity, and we now see similarly high rates of obesity in T1DM. Furthermore, T2DM remains uncommon in pre-pubertal children.
It is important not to assume a new diabetes diagnosis in obese youth is T2DM. While T2DM is increasingly common and important to consider, most youth presenting with symptoms consistent with hyperglycaemia will have T1DM. Without prompt diagnosis and treatment, they are at risk of severe clinical deterioration.
Ketosis may also be seen in youth with T2DM, and a severe presentation with DKA, the hyperosmolar hyperglycaemic syndrome, or a mixed picture may certainly be seen in youth with T2DM. A general index of suspicion and prompt discussion with a paediatric tertiary diabetes service and referral to emergency services is important in all youth with newly detected diabetes.
Missed diagnosis and differentials
Children with T1DM generally have symptoms for several weeks before diagnosis, becoming more obvious with time. A substantial proportion of children diagnosed with T1DM have interacted with the health care system and had an assessment by a healthcare provider at least once before a formal diagnosis of diabetes or presentation with DKA.
A delayed diagnosis of T1DM or DKA may be explained by symptoms that could be rationalised or diagnosed as something else. For example:
- polyuria – urinary tract infections
- Kussmaul breathing – the tachypnoea and respiratory distress of a respiratory tract infection
- polydipsia – increased thirst due to heat or increased physical activity (i.e. in summer)
- vomiting – gastroenteritis
- abdominal pain (which can be caused by ketosis/DKA) – other common childhood illnesses
- weight loss – intentional attempted weight loss in overweight children or accelerated linear growth, especially in adolescents. Weight loss in growing children should always raise concern and a diagnosis of diabetes be considered.
Other less classical symptoms include behavioural disturbance, reduced school performance, blurred vision, impairment of growth and recurrent candidiasis.
The next steps once you suspect diabetes?
If a patient presents with non-specific symptoms such as abdominal pain, nausea/vomiting or rapid, deep breathing (regardless of age or weight), get a blood glucose level (and a ketone level if possible). Patients with DKA can deteriorate quickly. Mortality is < 1% in Australia and due mainly to cerebral injury, but morbidity due to complications such as more subtle neurocognitive insult, acute kidney injury, venous thrombosis and pancreatitis can occur. All, however, are potentially preventable if hyperglycaemia in the differential diagnosis is considered early.
If the BGL is >11 mmol/l (or fasting blood glucose >7 mmol/L in a less acute situation), the patient should be discussed immediately with the local on-call endocrinology team. Where there is any question about T1DM, the patient should be sent to the ED. Once stabilised, patients and families will undertake education with the multi-disciplinary diabetes team (nurse educators, dietitians, social workers and endocrinologists) with close outpatient support and follow-up to coordinate care after discharge home from hospital.
The international standard of care is that all youth have access to at least quarterly diabetes clinic visits and 24/7 access to emergency phone support for diabetes-related acute concerns. All youth in Western Australia (approximately 1200 with T1DM and 100 with T2DM, with approximately 150 new children diagnosed annually) receive tertiary-level care through the Diabetes Service based at Perth Children’s Hospital.
Where possible this is provided every three months in age-grouped multi-disciplinary clinics. Approximately 40% of the service’s state-wide diabetes clinical care is provided in regional WA. These regional clinics are fully staffed by the Perth Children’s Hospital diabetes team. Partnering with our colleagues in general and community practice settings is highly valued and important for optimal outcomes for all youth with diabetes.
– References available on request
ED: Dr Black is an advanced trainee in paediatric endocrinology and Dr Taplin is a paediatric endocrinologist at Perth Children’s Hospital
Author competing interests – nil