Pediatric Type 1 Diabetes Mellitus Clinical Presentation

Updated: Nov 21, 2022
  • Author: William H Lamb, MD, MBBS, FRCP(Edin), FRCP, FRCPCH; Chief Editor: Sasigarn A Bowden, MD, FAAP  more...
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The most easily recognized symptoms of type 1 diabetes mellitus (T1DM) are secondary to hyperglycemia, glycosuria, and DKA.


Hyperglycemia alone may not cause obvious symptoms, although some children report general malaise, headache, and weakness. Children may also appear irritable and become ill-tempered. The main symptoms of hyperglycemia are secondary to osmotic diuresis and glycosuria.


This condition leads to increased urinary frequency and volume (eg, polyuria), which is particularly troublesome at night (eg, nocturia) and often leads to enuresis in a previously continent child. These symptoms are easy to overlook in infants because of their naturally high fluid intake and diaper/napkin use.


Increased thirst, which may be insatiable, is secondary to the osmotic diuresis causing dehydration.

Weight loss

Insulin deficiency leads to uninhibited gluconeogenesis, causing breakdown of protein and fat. Weight loss may be dramatic, although the child's appetite usually remains good. Failure to thrive and wasting may be the first symptoms noted in an infant or toddler and may precede frank hyperglycemia.

Nonspecific malaise

Although this condition may be present before symptoms of hyperglycemia or as a separate symptom of hyperglycemia, it is often only retrospectively recognized.

Symptoms of ketoacidosis

These symptoms include the following:

  • Severe dehydration

  • Smell of ketones

  • Acidotic breathing (ie, Kussmaul respiration), masquerading as respiratory distress

  • Abdominal pain

  • Vomiting

  • Drowsiness and coma

Additional symptoms

Hyperglycemia impairs immunity and renders a child more susceptible to recurrent infection, particularly of the urinary tract, skin, and respiratory tract. Candidiasis may develop, especially in the groin and in flexural areas.


Physical Examination

Apart from wasting and mild dehydration, children with early diabetes have no specific clinical findings. A physical examination may reveal findings associated with other autoimmune endocrinopathies, which have a higher incidence in children with type 1 diabetes mellitus (eg, thyroid disease with symptoms of overactivity or underactivity and possibly a palpable goiter).

Cataracts are rarely presenting problems ; they typically occur in girls with a long prodrome of mild hyperglycemia.

Necrobiosis lipoidica usually, but not exclusively, occurs in people with diabetes. Necrobiosis most often develops on the front of the lower leg as a well-demarcated, red, atrophic area. The condition is associated with injury to dermal collagen, granulomatous inflammation, and ulceration. The cause of necrobiosis is unknown, and the condition is difficult to manage. It is also associated with poor metabolic control and a greater risk of developing other diabetes-related complications.

Diabetic retinopathy

The first symptoms of diabetic retinopathy are dilated retinal venules and the appearance of capillary microaneurysms, a condition known as background retinopathy. These changes may be reversible or their progression may be halted with improved diabetic control, although in some patients the condition initially worsens.

Subsequent changes in background retinopathy are characterized by increased vessel permeability and leaking plasma that forms hard exudates, followed by capillary occlusion and flame-shaped hemorrhages. The patient may not notice these changes unless the macula is involved. Laser therapy may be required at this stage to prevent further vision loss.

Proliferative retinopathy follows, with further vascular occlusion, retinal ischemia, and proliferation of new retinal blood vessels and fibrous tissue; the condition then progresses to hemorrhage, scarring, retinal detachment, and blindness. Prompt retinal laser therapy may prevent blindness in the later stages, so regular screening is vital.