CASE A 26-year-old female presents w ith a three month history of weight loss and
general lethargy.
She has a five year history of Type 1 diabetes for which she has been treated
with basal bolus insulin consisting of short acting insulin thrice dail y and
long acting insulin in the evenings .
Commensurate with her weight loss of 5 kg over the last three months she
has noticed that she has recently encountered more hypoglycaemic events
and has reduced her insulin requirements from 60 units per day to 38 units
daily.
She takes no medication other than the oral contraceptive pil l . She is a nonsmoker.
On examination she has a BMI of 2 1 .2 kg/m
2
and appears comfortable. Her
pulse is 68 beats per minute regular and her blood pressure is 1 1 8/70 mmHg.
There are no specific abnormalities of the chest, heait or abdomen but she has
a slight purplish-yellow , 2-3 cm nontender maculopapular rash on both shins .
Investigations reveal normal urine analysi s , hemoglobin , white cell count ,
serum sodium and plasma urea. Random glucose 1 80 mg% , HbA l c 6 .7 % , s
potassium 5 .7 mmol/L (3 .5-4 .9) .
1. What is the most appropriate explanation for the new symptoms?
2. Give only one investigation to reach the diagnosis.
3. Mention the differential diagnoses of this patient.