Suspected Salt Poisoning in a 2-Month-Old Infant in a UK Paediatric Unit: A Case Report

This case report presents a rare and life-threatening case of severe hypernatremia in a previously well 2-month-old infant.The child was admitted with lethargy and poor feeding and was found to have a serum sodium of 168 mmol/L, which rose rapidly to 198 mmol/L within 48 hours despite controlled fluid management verified by strict monitoring.Urinary sodium levels exceeded 200 mmol/L, and osmolality results indicated preserved concentrating ability, making dehydration and diabetes insipidus unlikely.The rapid and disproportionate biochemical abnormalities, along with clinical presentation and minimal weight loss, raised strong suspicion for intentional salt poisoning.Prompt multidisciplinary action, including renal, metabolic, and safeguarding teams, led to escalation of care, transfer to PICU, and social services involvement.Neuroimaging revealed subdural and subarachnoid haemorrhages.This case highlights the importance of considering non-accidental causes in infants with unexplained hypernatremia and illustrates the critical role of early safeguarding and coordinated multidisciplinary management.The infant was discharged stable under foster care with ongoing neurodevelopmental follow-up.