1. 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

2. History
A 34-year-old woman
Blurred vision OD

3. 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

4. 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.

5. Fluorescein angiographyB
(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.

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

7. Initial differential diagnosis
Toxoplasmosis
Tuberculosis
Syphilis
Herpes infection
Behçet disease
Sarcoidosis

8. 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

9. 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.

10. Final diagnosis
Ocular rickettsiosis

11. 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).

12. 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