Unmasking Adrenal Insufficiency: Adrenal Crisis Triggered by Influenza-Associated Encephalitis

Primary adrenal insufficiency, or Addison disease, can be caused by an autoimmune process and presents with poor growth, poor weight gain, nausea, vomiting, fatigue, and skin hyperpigmentation. During times of stress or illness, patients with untreated or insufficiently treated adrenal insufficiency are at risk for adrenal crisis progressing to hypotensive shock, lethargy, confusion, coma, and death. While primary adrenal insufficiency is reported as a rare cause of encephalopathy, and more rarely encephalitis in adults, it is not known to be associated with encephalitis in children. Here, we present a unique case of a female 17-year-old who presented with significant encephalopathy and magnetic resonance imaging findings consistent with acute leukoencephalopathy with restricted diffusion and who was ultimately found to be in adrenal crisis secondary to influenza-related encephalitis. Due to rapidly declining neurologic function and concern for infectious encephalitis, the new diagnosis of adrenal insufficiency was not initially identified. Less common electrolyte derangements, including hypercalcemia and hyperphosphatemia, also contributed to difficulties in diagnosis. After initiation of steroid replacement, the patient progressed to make remarkable functional progress. This case underscores the importance of navigating diagnostic uncertainty in complex pediatric care to improve patient outcomes. In addition, this case contributes to the growing literature of primary adrenal insufficiency in the pediatric patient and demonstrates the important role of glucocorticoids on neurologic function and calcium/phosphate metabolism.