A young woman is lethargic and hypotensive (80/60 mmHg). Her skin has a diffuse bronze tone and there are brown patches on the buccal mucosa. The MOST likely diagnosis is:

Correct answer: C. Addison disease (primary adrenal insufficiency)

• A. ❌ Peutz-Jeghers produces discrete perioral and mucosal macules with intestinal polyposis, but no hypotension or systemic collapse.
• B. ❌ Hemochromatosis bronzes the skin but does not cause hypotension or the characteristic mucosal patches.
• C. ✅ CORRECT — Primary adrenal insufficiency removes cortisol's negative feedback, so ACTH and its precursor POMC rise. The melanocyte-stimulating fragment of POMC causes the bronze skin and DIFFUSE ORAL MELANOTIC PIGMENTATION. Add hypotension, fatigue, weight loss, salt craving and hyperkalemia and the picture is complete.
• D. ❌ Cushing syndrome (cortisol EXCESS) causes hypertension, central obesity, moon facies and a buffalo hump — the reverse of this picture.

Note: Dental relevance: these patients are at risk of ADRENAL CRISIS under stress. Consult the physician about supplemental steroid coverage, keep appointments short and stress-free, and know that hypotension unresponsive to positioning needs emergency care.