A Zebra of Adrenal Insufficiency, what was once common-now rare

Background: TB was once a common cause of primary adrenal insufficiency, it is now most often autoimmune in the developed world, but there are rarely observed infectious causes, including TB, Fungal, and CMV. The extra-adrenal manifestations typically stem from pulmonary TB. When TB invades the adrenals, imaging of the adrenal glands initially shows hypertrophy, which progresses to fibrosis and calcification in almost half the cases. This adrenal hypertrophy is often a key marker for differentiating tuberculous adrenal insufficiency from autoimmune adrenalitis, in which case adrenals are usually atrophied. Case: A 62 year old woman with a history of CKD, hyperlipidemia, and possible heart failure presented to the hospital with a 3 week history of worsening right knee pain. She was initially hypotensive at 68/48. Her hospital course was complicated by renal failure, persistent hypotension, and hyponatremia. She received approximately 5 liters of fluid with no significant hemodynamic response. Initial labs showed sodium of 125 with normal range 135-145 and a creatinine of 3.63 with sodium levels hovering in the low 130’s throughout the next 8 days while systolic pressure remained less than 110. Endocrinology was consulted to evaluate the ongoing hypotension and hyponatremia 5 days into admission. Infectious disease was also consulted after it was later revealed that the patient had a history of TB with a positive ppd in 2014, treated with Isoniazid but she was unable to confidently state whether she completed treatment. Other lab work was remarkable for a positive ppd test, negative HIV, and random cortisol levels of 1.3 and 1.1. Cosyntropin stimulation test was very abnormal with cortisol results of 1.3 and 1.1 at 30 and 60 minute intervals (normal \u3e18). ACTH on day 6 of admission was greater than 2000, consistent with primary adrenal insufficiency. Abdominal CT without contrast on day 11 showed adrenal fullness with nodal calcifications consistent with post-infectious TB. Blood pressure and sodium improved on hydrocortisone 50 mg three times daily. She was discharged on hydrocortisone 20mg in the AM and 10mg in the PM, fludrocortisone 0.1mg daily and the 4 drug combo for TB; Rifampin, Isoniazid, Pyrazinamide, and Ethambutol. Conclusion: This case of primary adrenal insufficiency highlights an atypical cause that is now rare in the developed world. TB causes adrenal destruction in a gradual manner, targeting the medulla and cortex secondarily as illustrated here by this HIV-negative latent TB patient. Tuberculous adrenal insufficiency typically presents in an insidious manner. This case demonstrates the importance of a thorough history and evaluation coupled with the realization that not all primary adrenal insufficiency is autoimmune