Acute Renal Failure with Severe Hyperkalaemia Revealing Schmidt Syndrome

Abstract: Background: Schmidt’s syndrome, or type II autoimmune polyendocrinopathy, is characterized by the coexistence of autoimmune conditions, most commonly Addison’s disease, autoimmune thyroiditis, and gonadal insufficiency. Addison’s disease, though rare, may present with acute renal failure, complicating timely diagnosis and treatment. Case Presentation: We report a case of a 21-year-old female presenting with nonspecific gastrointestinal symptoms, severe asthenia, hypotension, and secondary amenorrhoea. Laboratory investigations revealed acute renal failure, hyperkalaemia, hyponatraemia, hypothyroidism, and primary ovarian failure. Clinical re-evaluation noted hyperpigmentation suggestive of Addison’s disease, confirmed by markedly reduced serum cortisol, elevated ACTH, and positive anti-21-hydroxylase antibodies. Imaging showed adrenal atrophy. Prompt initiation of intravenous hydration and hydrocortisone led to rapid clinical and biochemical improvement, including restoration of menstrual cycles. Discussion: This case highlights the diagnostic challenge of Addison’s disease, especially when masked by renal failure symptoms. The underlying pathophysiology involves combined glucocorticoid and mineralocorticoid deficiency, leading to volume depletion, electrolyte imbalance, and reduced renal perfusion. Early recognition and hormone replacement are crucial to prevent potentially life-threatening outcomes. Conclusion: Addison’s disease, particularly as part of Schmidt’s syndrome, should be considered in patients presenting with unexplained renal failure, electrolyte disturbances, and endocrine abnormalities. Timely diagnosis and corticosteroid replacement can result in dramatic clinical recovery.