Life-Threatening Calcium Chloride Ingestion.

Calcium chloride dihydrate (CaCl₂·2H₂O), a common component in household dehumidifiers in South Korea, poses a significant risk of toxicity upon ingestion. We present a case of life-threatening hypercalcemia following intentional calcium chloride dihydrate ingestion, with a focus on electrolyte homeostasis and physiological adaptation. An 86-year-old Korean woman presented with transient unconsciousness after ingesting dehumidifier fluid. She exhibited drowsiness and developed sinus tachycardia 10 h later. Severe hypercalcemia (19.4 mg/dL) was the main biochemical disturbance. Parathyroid hormone was initially suppressed but later rose, facilitating renal calcium excretion and phosphorus regulation. Electrolyte levels normalized by day 4. Prompt treatment, including gastric lavage and cardiac management, led to a full recovery. A rapid parathyroid hormone response played a crucial role in restoring calcium balance.