Panuveitis Associated With Idiopathic Hypereosinophilic Syndrome

<b>Purpose:</b> To describe a patient with idiopathic hypereosinophilic syndrome (HES) associated with panuveitis. <b>Methods</b>: An interventional case report is presented. <b>Results:</b> A 70-year-old woman presented with intermittent cutaneous eruptions, bilateral panuveitis, and a ground-glass pattern on chest CT-scan, with isolated eosinophilia of 12.8 × 10⁹/L. A complete uveitis workup was performed, and the patient was evaluated to rule out secondary causes of eosinophilia, with a thorough focus on infections, eosinophilic granulomatosis with polyangiitis, sarcoidosis, and drug-related syndromes. A bone marrow biopsy ruled out primary eosinophilia. Cytogenetics were also negative. Under steroid treatment there was no recurrence of skin rashes and panuveitis was satisfactorily resolved, but further use of mepolizumab was needed to normalize the hemogram. <b>Conclusions:</b> The diagnosis of HES requires a comprehensive evaluation. Ocular involvement is rare. We present the ocular findings during the acute stage for the first time, along with the current management approach.