Food poisoning or adrenal insufficiency? The role of hyperkalemia in guiding the diagnosis

Abstract

Background. Hyperkalemia (>5.9 mmol/L) has multifactorial causes. Although it is frequently associated with renal insufficiency, hyperkalemia is also a manifestation of adrenal insufficiency, especially during acute decompensation. Identifying the underlying cause of hyperkalemia is essential for appropriate management. Objective(s). To highlight the importance of hyperkalemia as a diagnostic marker in identifying severe conditions, such as hypocortisolism, in seemingly benign contexts like suspected food poisoning. Materials and methods. We present the case of a 29-year-old patient who presented to Medpark Hospital in the summer of 2018 with recurrent episodes of vomiting and diarrhea, salt craving, epigastric pain, asthenia, and somnolence, which began suddenly after consuming citrus fruits, initially raising suspicion of food poisoning. The final diagnosis was Addison’s disease. Results. Objective examination revealed skin hyperpigmentation and low-grade fever. Laboratory findings showed hyponatremia 126.0 mmol/L (135–145 mmol/L) and hyperkalemia 6.73 mmol/L (3.5–5.1 mmol/L), with normal renal function. Notably, potassium levels rose to 7.11 mmol/L six hours after initial treatment. The abrupt symptom onset, skin hyperpigmentation, treatment-resistant hyperkalemia, and absence of renal pathology prompted adrenal evaluation. Hormonal tests confirmed low cortisol 1.8 µg/dL (5–25 µg/dL), low aldosterone 2.7 ng/dL (5–30 ng/dL), and elevated ACTH 81 pg/mL (10– 60 pg/mL), establishing the diagnosis of Addison’s disease. Conclusion(s). Hyperkalemia may serve as an early warning sign for acute adrenal insufficiency. Therefore, hyperkalemia should always be interpreted in conjunction with the clinical and paraclinical picture, as it may represent the first indicator of a life-threatening systemic disorder.