FRI212 Adrenalitis Caused By Proteus Mirabilis In An Immunocompetent Patient

Disclosure: J.O. Abdelkarim: None. U. Tarabichi: None. M. Jakoby: None. Infectious adrenalitis with Mycobacterium tuberculosis remains the leading cause of primary adrenal insufficiency in developing countries, but the incidence of adrenalitis from infection with other bacterial species is quite low. We present a patient with radiographic evidence of adrenalitis during an infection with Proteus mirabilis that resolved after antimicrobial treatment.An 86-year-old male with an indwelling Foley catheter presented to the hospital for evaluation of abdominal pain and distension. The patient was afebrile and normotensive. Examination was notable for a distended bladder and obstructed urinary catheter. Computed tomography (CT) revealed a dense right lower lobe infiltrate and bilaterally enlarged, hypointense adrenal glands with irregular margins. Radiographic findings were new compared to a CT scan obtained approximately 10 weeks before admission to hospital. Turbid and malodorous urine was drained after replacement of the patient’s urinary catheter, and urine culture grew > 10(5) CFU/mL Proteus mirabilis. Antibiotics were dosed before blood cultures were drawn, and no organisms were grown from blood cultures. Since there was no clinical or biochemical evidence (e.g. hyponatremia or hyperkalemia) of primary adrenal insufficiency, an ACTH stimulation test was deferred. The patient responded well to replacement of his urinary catheter and antibiotics and was discharged to his extended care facility three days later. A CT scan obtained 10 days after treatment showed resolution of the changes to the patient’s adrenal glands observed on admission imaging.The radiographic changes are most plausibly due to P. mirabilis bacteremia and adrenalitis. The patient had urine culture confirmed infection with P. mirabilis and radiographic evidence of disseminated infection in the right lung and adrenal glands. Adrenal enlargement is well described in cases of acute M. tuberculosis adrenalitis, and radiographic changes of adrenalitis resolved after successful treatment of the patient’s infection. P. mirabilis has been documented as an etiology of Waterhouse-Friderichsen syndrome and cultured from an adrenal abscess. Blood cultures in this case were almost certainly negative due to timing relative to initial antibiotic doses. Injury to the adrenals in bacterial adrenalitis is thought to occur due to multiple mechanisms including direct infection of the glands, endotoxemia, vasculitis, and disseminated intravascular coagulation (DIC). Hemorrhage appears to occur in about 60% of cases. Elevated ACTH level is postulated as a factor predisposing to adrenal hemorrhage, and this prompted deferral of stimulation testing to evaluate adrenal function since there was no clinical evidence of primary adrenal insufficiency. Early management of the patient’s infection likely prevented the occurrence of adrenal insufficiency and deterioration of his clinical status. Presentation: Friday, June 16, 2023