Diagnostic Analysis With the low cortisol level, the diagnosis of Addison disease was made. Her ACTH was high, indicating secondary adrenal failure. ACTH has actions comparable to melanocytic-stimulating hormone thus causing hyperpigmentation, and elevated levels of ACTH caused this woman to be very darkly tanned. No pituitary tumor was found indicating that this was primary adrenal failure. Her elevated ANA and hydroxylase antibodies indicated that she had an autoimmune cause of her Addison’s disease. The small or absent adrenal glands noted on CT scan corroborated autoimmune destruction of her adrenal glands. Although one of her main presenting symptoms was upper GI dysfunction, no pathology, such as peptic disease, was found. Her reduced gastric transit was caused by her Addison disease. Critical Thinking Questions
1. Of all the tests this young woman had, which single test would be easiest, most diagnostic, and would have explained her entire symptom complex?
2. What are some of the other adrenal function tests that could have been performed to assist in the diagnosis of this woman’s adrenal failure?
3. What is the difference between primary and secondary Addison disease, and how can the two be separated?
4. Why was this woman’s sodium low and her potassium elevated?
Sample Solution
