PRIMARY ADRENAL INSUFFICIENCY SECONDARY TO BILATERAL ADRENAL TUBERCULOSIS DURING ANTI-TUBERCULOSIS TREATMENT

INTRODUCTION/BACKGROUND Adrenal tuberculosis (TB) is a rare but serious form of extrapulmonary TB, accounting for 7% to 20% of primary adrenal insufficiency (PAI) cases worldwide. It typically results from haematogenous spread, leading to granulomatous inflammation, caseous necrosis and progressive adrenal destruction. Despite appropriate anti-TB therapy, PAI can develop weeks to months later due to ongoing adrenal damage. CASE A 68-year-old Malay male with type 2 diabetes mellitus, hypertension and ischaemic heart disease was recently diagnosed with miliary TB and had been on anti-TB treatment (EHRZ regimen) for 43 days. He presented with a two-day history of lethargy, poor oral intake and postural giddiness. Upon arrival, he appeared cachectic, with hyperpigmentation over the knuckles, a blood pressure of 88/71 mm Hg, and a heart rate of 99 bpm. Given his persistent hypotension despite fluid resuscitation, adrenal crisis was suspected, and intravenous hydrocortisone was initiated. His laboratory tests showed a low random cortisol level of 21 nmol/L and an elevated ACTH level of 143 pmol/L (reference range: 1.6–13.9 pmol/L), confirming PAI. A Computed Tomography (CT) scan of the adrenal glands revealed bilateral adrenal enlargement with peripheral enhancement and central necrosis, consistent with adrenal TB. Anti-TB treatment was continued, and hydrocortisone was gradually tapered to 20 mg in the morning and 10 mg in the evening. He required a higher maintenance dose due to concurrent rifampicin therapy. CONCLUSION This case highlights the importance of early recognition of adrenal insufficiency in TB patients. Delayed-onset PAI can occur despite ongoing therapy, necessitating a high index of suspicion and prompt glucocorticoid replacement to prevent adrenal crisis. Additionally, clinicians should be mindful of rifampicin-induced glucocorticoid metabolism, which often necessitates higher maintenance doses of glucocorticoids in affected patients.