Endocrine Abstracts

Insulin oedema is uncommon and poorly understood. It has been reported mainly in the adult literature. We present one of the youngest cases reported in the literature.

A previously obese 9-year-old boy gradually lost weight over 18-month period and experienced polyuria and polydipsia for several months. He presented in diabetic ketoacidosis (blood glucose 24 mmol/l, pH 7.13, bicarbonate 6.6 mmol/l, potassium 3.13 mmol/l, urinary ketones 3+) which responded well to treatment. Admission weight was 37.4 kg, height 149.8 cm and BMI 16.7. He developed significant hypokalaemia and required increased concentrations of KCl in the intravenous fluids (35 mmol/500 ml) to maintain normal levels. Recovery was otherwise uneventful and was discharged on basal bolus insulin regime. From 5 days post initiation of insulin therapy, he developed increasing generalised oedema. By the 8th day, he gained a significant amount of weight of 11.8 kg and had periorbital, leg, thigh and scrotal oedema. He was extremely well. No renal, hepatic or cardiac cause for oedema was found. Abdominal ultrasound was normal including inferior vena cava and iliac veins. He was treated conservatively and the oedema resolved over 4 weeks. Over next 19 months, he gained weight dramatically despite ever decreasing insulin requirements. Currently aged 11.5 years, his height is 163.8 cm, weight 95 kg and BMI 35.4. Insulin requirement is only 13 units/day and is also on Metformin. HbA1c is 5.7%. There is no family history of diabetes. Further investigations showed GAD antibody negative, MELAS m.3243 A>G & 3271 T>C mutation negative.

This case highlights the importance of recognizing insulin oedema, a worrying but benign complication of insulin therapy. This case also presented a diagnostic quandary making it difficult to classify the type of diabetes he had.