Revisiting Eosinophilia: A Neglected Indicator of Adrenal Insufficiency.

Diagnosing adrenal insufficiency is challenging due to its nonspecific symptoms and insidious onset. We report the case of a 55-year-old woman who developed persistent eosinophilia accompanied by nausea, vomiting, fatigue, muscle weakness, dizziness, and brain fog following her second COVID-19 vaccination. A comprehensive evaluation ultimately led to the diagnosis of adrenal insufficiency. Her symptoms and eosinophilia resolved with corticosteroid therapy. This case demonstrated an unusual presentation of adrenal insufficiency and the importance of considering it in the differential diagnosis when eosinophilia is present. By remaining vigilant regarding the diverse clinical presentations of adrenal insufficiency, we can facilitate timely diagnosis with a more cost-effective approach.