Aortitis Secondary to Cogan's Syndrome: A Rare Cause of Fever of Unknown Origin.

Fever of unknown origin remains a diagnostic challenge. Aortitis, defined as inflammation of the aorta, has multiple infectious and non-infectious causes. We report the case of an elderly woman with vertigo and bilateral hearing loss, presenting with fever of unknown origin. Blood tests were remarkable for leucocytosis with neutrophilia, elevation of C-reactive protein and the erythrocyte sedimentation rate, and positive antinuclear antibodies and rheumatoid factor, and an unremarkable search for multiple infectious causes of fever. During admission the patient developed a bilateral red eye. Abdominal and chest computed tomography was performed and demonstrated signs of aortitis. Due to the coexistence of aortitis, ocular inflammation, vertigo and bilateral hearing loss in a patient with persistent fever and elevation of inflammatory parameters, a presumptive diagnosis of Cogan's syndrome was made, with improvement after initiation of steroid therapy. LEARNING POINTS: Fever of unknown origin is a diagnostic challenge with an extensive list of possible causes.The coexistence of fever, aortitis, ocular and vestibulo-cochlear symptoms should raise the suspicion of Cogan's syndrome.Steroid therapy is the first-line treatment for Cogan's syndrome.