Background: Because persistent fever often occurs in adrenal insufficiency, it might be confused with infectious diseases. This study aimed to identify clinical characteristics and risk factors of patients with adrenal insufficiency and fever. Methods: All adult patients (n = 150) admitted to a tertiary care hospital in South Korea and diagnosed with adrenal insufficiency between 1 March 2018, and 30 June 2019, were recruited. Patients were excluded if they had: 1) proven structural problems in the adrenal or pituitary gland; 2) a history of chemotherapy within 6 months prior to the diagnosis of adrenal insufficiency; and 3) other medical conditions that may cause fever. Results: Among the included patients, 45 (30.0%) had fever at the time of the diagnosis of adrenal insufficiency. The mean C-reactive protein level was higher (11.25 ± 8.54 vs. 4.36 ± 7.13 mg/dL) in patients with fever than in those without fever. A higher proportion of patients with fever changed antibiotics (33.3% vs. 1.0%). On multivariate logistic regression analysis, female sex (odds ratio [OR], 0.32) lowered the risk of adrenal insufficiency with fever, while a history of surgery within 6 months (OR, 4.35), general weakness (OR, 7.21), and cough (OR, 17.29) were significantly associated with that. Conclusion The possibility of adrenal insufficiency should be considered in patients with fever of unknown origin, especially those with risk factors.

Background: Because persistent fever often occurs in adrenal insufficiency, it might be confused with infectious diseases. This study aimed to identify clinical characteristics and risk factors of patients with adrenal insufficiency and fever. Methods: All adult patients (n = 150) admitted to a tertiary care hospital in South Korea and diagnosed with adrenal insufficiency between 1 March 2018, and 30 June 2019, were recruited. Patients were excluded if they had: 1) proven structural problems in the adrenal or pituitary gland; 2) a history of chemotherapy within 6 months prior to the diagnosis of adrenal insufficiency; and 3) other medical conditions that may cause fever. Results: Among the included patients, 45 (30.0%) had fever at the time of the diagnosis of adrenal insufficiency. The mean C-reactive protein level was higher (11.25 ± 8.54 vs. 4.36 ± 7.13 mg/dL) in patients with fever than in those without fever. A higher proportion of patients with fever changed antibiotics (33.3% vs. 1.0%). On multivariate logistic regression analysis, female sex (odds ratio [OR], 0.32) lowered the risk of adrenal insufficiency with fever, while a history of surgery within 6 months (OR, 4.35), general weakness (OR, 7.21), and cough (OR, 17.29) were significantly associated with that. Conclusion The possibility of adrenal insufficiency should be considered in patients with fever of unknown origin, especially those with risk factors.