Rickettsiosis Rim Kahloun, MD Bechir Jelliti, MD Salim Ben Yahia, MD Moncef Khairallah, MD Department of Ophthalmology Fattouma Bourguiba University Hospital Faculty of Medicine, University of Monastir Monastir, Tunisia

History A 34-year-old woman Blurred vision OD

September 2013: First Presentation Visual acuity: 20/20 OU No cells or flare in anterior chamber OU 1+ vitreous cells OS Intraocular pressure: 12 mmHg OD, 13 mmHg OS

Fundus examination of the OD shows a white retinal lesion adjacent to the superior vascular arcade, close to the optic disc, with associated retinal hemorrhages.

Fluorescein angiography B (A) Early-phase fluorescein angiogram OD shows hypofluorescence of the retinal lesion. (B) Late-phase fluorescein angiogram shows staining of the retinal lesion with retinal vascular leakage.

Optical coherence tomography OCT shows increased internal retinal reflectivity with associated retinal thickening, serous retinal detachment, and posterior shadowing

Initial differential diagnosis Toxoplasmosis Tuberculosis Syphilis Herpes infection Behçet disease Sarcoidosis

Work-up PCR on aqueous humor: negative for toxoplasmosis and herpes viruses Serology for syphilis: negative Mantoux test and quantiferon: negative No clinical features of Behçet´s disease Work-up for sarcoidosis: negative

Work-up History retaking: fever, headache, skin rash few weeks earlier Serological testing for rickettsial infections: positive for Rickettsia conorii Oral doxycycline 200 mg/day for 2 weeks.

Final diagnosis Ocular rickettsiosis

Follow-up Two months later Visual acuity: 20/20 Fundus photograph shows a significant resolution of the active retinal lesion. Note the presence of periarteriolar plaques (Kyrieleis arteritis).

Conclusion Rickettsial disease should be considered in the differential diagnosis of: Inner retinitis with mild or moderate vitritis, retinal vasculitis, and optic neuropathy In a patient: - with a history of high fever, headache, and skin rash - living in or traveling back from a region endemic for rickettssial disease, especially during the spring or summer