Practice Easily Missed?

Type 1 diabetes in children

BMJ 2011; 342 doi: http://dx.doi.org/10.1136/bmj.d294 (Published 16 February 2011) Cite this as: BMJ 2011;342:d294
  1. Keya Ali, consultant paediatrician1,
  2. Anthony Harnden, university lecturer in general practice and general practitioner2,
  3. Julie A Edge, consultant in paediatric diabetes1
  1. 1Oxford Children’s Hospital, John Radcliffe Hospital, Oxford OX3 9DU
  2. 2Department of Primary Health Care, Oxford OX3 7LF
  1. Correspondence to: J A Edge julie.edge{at}paediatrics.ox.ac.uk

Type 1 diabetes in childhood is one of the commoner long term conditions of childhood. It is treated by specialist teams in secondary care using increasingly intensive insulin regimens, but the onset is generally diagnosed by primary care physicians, sometimes later than is ideal.

Case scenario

A 7 year old boy with acute abdominal pain and vomiting is brought to see his general practitioner by his mother. He was being bullied at school, and because his mother attributed his recent onset of bed wetting to stress she did not mention this symptom to the GP. The GP considers appendicitis a possibility but first decides to rule out a urinary tract infection. A urine dipstick test is positive for glucose and ketones. She refers the child at once to the paediatric team for immediate management of his diabetic ketoacidosis.

How common is it?

  • In England diabetes occurs in 1 in 450 children, of whom 97% have type 1 diabetes mellitus1

  • The current incidence is around 26/100 000 per year

  • In a large UK general practice, a child with new diabetes will be seen about every two years

  • Incidence is increasing by around 4% a year in the UK, in common with other northern European countries2

  • The prevalence of diabetic ketoacidosis at diagnosis over the past 20 years has remained unchanged, at around 25% of newly diagnosed children of all ages and 35% in children under 5 years3 4

Why is it missed?

About 30% of children with newly diagnosed diabetes have had at least one related medical visit before the diagnosis, suggesting that medical practitioners are missing the diagnosis.5 Drinking a lot and passing a lot of urine may not be mentioned by parents, even when children start bed wetting after having been dry. Other early symptoms of diabetes in young children (headache, constipation, oral and vulval thrush, abdominal pain, vomiting) may be non-specific. In older children and adolescents, polyuria and polydipsia usually predominate, but these symptoms can be misinterpreted by parents and schools or ignored by adolescents. Doctors may not consider the diagnosis as a cause of the initial symptoms; they may fail to ask about polyuria and polydipsia in children with other suggestive symptoms or may fail to carry out the appropriate investigation. Incorrect diagnoses in children with newly presenting diabetes include respiratory infection, simple candidiasis, gastroenteritis, urinary tract infection, stomatitis, and appendicitis.6

Why does this matter?

Children can develop dehydration and acidosis within 24 hours of first presentation, and children aged under 2 years are most at risk. In a recent UK study, a higher proportion of children with delayed diagnosis presented in diabetic ketoacidosis than did those with no delay (52% v 21%).7 Diabetic ketoacidosis is the leading cause of mortality and morbidity in children with type 1 diabetes mellitus; 10 children a year die from diabetic ketoacidosis in the UK. Most diabetes related deaths are due to cerebral oedema, which is more common when diabetic ketoacidosis occurs at onset of diabetes.8

How is type 1 diabetes diagnosed in children?

Clinical features

Clinical features can be non-specific in children under 2 years, and a high index of suspicion is important. Polyuria and polydipsia are the main symptoms of diabetes in all age groups, occurring in up to three quarters of school age children.9 However, these symptoms are not always mentioned initially and must be elicited by a proper history taking. Nocturnal enuresis in a previously “dry” child is the earliest symptom of diabetes in 89% of children over the age of 4 years.9 10 Weight loss occurs in half those aged 10-14 years but in only 5% of children under 2 years. Lethargy occurs in 10-20% of children of all ages. Constipation is an important symptom in the under 5s, occurring in around 10%, secondary to chronic dehydration.9 Recurrent infections are uncommon as a presentation, occurring in only 2%, although oral and vulval thrush has been reported. Positive predictive values of these symptoms are not known as the appropriate research has not been carried out.

If ketoacidosis has already supervened, then the symptoms can include vomiting, deep sighing respiration, reduced conscious level, and abdominal pain. Because of these, diabetic ketoacidosis can be misdiagnosed as acute abdomen, possible gastroenteritis, acute asthma, or pneumonia if the parents are not asked about a history of polyuria and polydipsia.

Investigations

Diabetes can be diagnosed with a single capillary blood glucose test if a proper technique has been followed—that is, the child’s hands have been washed and dried thoroughly. The diagnostic criteria for diabetes are the same in children as in adults: a random blood glucose concentration >11.1 mmol/L. Any delay obtaining a urine sample or a glucose measurement may allow diabetic ketoacidosis to supervene. If symptoms suggest diabetes, the consultation should not finish until a diagnosis has been made or diabetes ruled out. Children should not wait for a fasting blood glucose test. The capillary blood glucose results will be confirmed with a laboratory testing of blood glucose when the child arrives in hospital.

How is it managed?

Refer a child or young person with a high capillary blood glucose concentration promptly (same day) to secondary care for further management.

Children with type 1 diabetes require insulin, which is given in various regimens and is started on the day of referral. The management, education, and support are carried out by a multidisciplinary team based in secondary care, consisting of doctors, diabetes specialist nurses, and dietitians. Many centres are starting to use multiple injection regimens in most age groups (using basal and rapid insulin four to six times daily). Other possible regimens are two or three injections per day of various combinations of insulin types. Educating the child and family is the keystone of management, as families will need rapidly to learn all of the practical techniques required to give insulin injections, measure blood glucose, and treat mild hypoglycaemia. Most centres admit children to hospital for up to 48 hours, but some have the resources to send children home on the first night, with follow-up and education at home.

An aggressive and relatively inexpensive campaign of information aimed at health professionals and the public on the early symptoms of diabetes dramatically reduced the incidence of diabetic ketoacidosis at diagnosis of type 1 diabetes in children in Italy.10 A similar campaign should be tried in the UK.

Key points

  • Secondary nocturnal enuresis is the commonest symptom of new diabetes in children

  • Ask about polyuria and polydipsia in toddlers with constipation, thrush, vomiting, weight loss, or any acute illness

  • Investigate children with polyuria, polydipsia, and weight loss for diabetes

  • Investigation for diabetes requires only a single immediate capillary blood glucose test; values above 11.1 mmol/L indicate diabetes

  • Refer children with a raised blood glucose concentration to secondary care the same day

  • Do not wait for a fasting blood glucose test or urine sample as this may allow diabetic ketoacidosis to intervene

Notes

Cite this as: BMJ 2011;342:d294

Footnotes

  • This is one of a series of occasional articles highlighting conditions that may be more common than many doctors realise or may be missed at first presentation. The series advisers are Anthony Harnden, university lecturer in general practice, Department of Primary Health Care, University of Oxford, and Richard Lehman, general practitioner, Banbury. To suggest a topic for this series, please email us at easilymissed{at}bmj.com.

  • Contributors: AH and JAE conceived the article; JAE and KA provided the background content about type 1 diabetes and its presentation and treatment, and AH provided the general practice perspective. All authors have provided input in the drafts. JAE is the guarantor.

  • Funding: No special funding.

  • Competing interests: All authors have completed the Unified Competing Interest form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years, no other relationships or activities that could appear to have influenced the submitted work.

  • Provenance and peer review: Not commissioned, externally peer reviewed.

  • Patient consent not required (patient hypothetical).

References