Adrenal insufficiency and adrenal crisis — formative SAQs

SAQ 1 — The pigmented, losing-weight adolescent (20 marks, ~15 minutes)

A 14-year-old girl presents with four months of fatigue, nausea, abdominal pain and a 6 kg weight loss. Her mother says she has "gone brown". On examination she is tanned in the palmar creases, gum margins and old scars, with a postural drop in blood pressure. Sodium 126 mmol per litre, potassium 5.9 mmol per litre, glucose 2.6 mmol per litre. She has type 1 diabetes and autoimmune thyroiditis. [7]

Questions

1. Give the most likely diagnosis, the single set of first-line bloods that confirms it, and the expected ACTH and renin results. (5 marks) [1]
2. Outline the first-hour resuscitation if she collapses in the department, and state why treatment is not delayed for a confirmatory result. (5 marks) [4]
3. Explain the link to her type 1 diabetes and thyroiditis, and the further screening this implies. (4 marks) [7]
4. Describe the lifelong replacement regimen and the stress-dose and emergency plan you give the family. (6 marks) [1]

Model answer (must-hit)

1. This is primary adrenal insufficiency (autoimmune Addison disease) until proven otherwise. The hyperpigmentation, weight loss, postural hypotension, and the hyponatraemia with hyperkalaemia and hypoglycaemia are the full primary picture. Send a morning cortisol, ACTH, renin and aldosterone: cortisol is low, ACTH and renin are high, and aldosterone is low. Confirm with a 250-microgram cosyntropin stimulation test and 21-hydroxylase antibodies. [1]
2. Resuscitate on three tracks: 10 to 20 mL per kg of 0.9% saline repeated to perfusion; parenteral hydrocortisone 50 to 100 mg intravenously stat then 50 to 100 mg per square metre per 24 hours; and intravenous dextrose for the hypoglycaemia, with cultures and empiric antibiotics because sepsis coexists. The cortisol and ACTH confirm but do not resuscitate, so hydrocortisone is given empirically before the results return. [4]
3. Autoimmune Addison disease clusters with type 1 diabetes and autoimmune thyroiditis in autoimmune polyglandular syndrome type 2, so her presentation is the third endocrinopathy. Screen for the associated autoimmune diseases — thyroid function, coeliac screen, vitamin B12 and parietal-cell antibodies, gonadal status — and counsel the family, because a child with type 1 diabetes who develops fatigue and pigmentation has Addison until tested. [7]
4. Start oral hydrocortisone 8 to 12 mg per square metre per day in three divided doses with a larger morning dose, and add fludrocortisone 0.05 to 0.2 mg per day because she has primary disease. Build a stress-dose plan: double or triple the oral hydrocortisone for any febrile illness, give parenteral hydrocortisone if she vomits, and issue a parent-held emergency intramuscular hydrocortisone kit (adolescent 100 mg) with a MedicAlert and a school care plan. [1]