Addison's disease due to tuberculosis that required differentiation from SIADH

Area of Science:

• Endocrinology
• Infectious Diseases
• Radiology

Background:

• Hyponatremia can be a presenting symptom of various conditions, including endocrine disorders and infections.
• Tuberculosis can affect multiple organs, including the adrenal glands, potentially leading to adrenal insufficiency.
• Syndrome of Inappropriate Antidiuretic Hormone secretion (SIADH) is a common cause of hyponatremia, often associated with malignancies or infections.

Observation:

• A 77-year-old male presented with fatigue and severe hyponatremia (serum sodium 116 mEq/l).
• FDG-PET imaging suggested SIADH secondary to extrapulmonary tuberculosis, with brain and adrenal nodules observed.
• The patient's condition deteriorated upon initiation of anti-tuberculosis therapy.

Findings:

• Hormonal tests confirmed Addison's disease as the underlying cause of hyponatremia.
• High-dose hydrocortisone administration led to immediate clinical improvement.
• Anti-tuberculosis medications resulted in the reduction of tuberculous lesions.

Implications:

• Adrenal insufficiency, specifically tuberculous Addison's disease, should be considered in patients with hyponatremia and active or past tuberculosis.
• Prompt diagnosis and appropriate management, including corticosteroid replacement, are vital for patient recovery.
• Despite decreasing incidence, vigilance for tuberculous Addison's disease remains important in clinical practice.