[Focus on Susac's syndrome. A pediatric case report]

Susac's syndrome (SS) is a rare immune disorder. It combines encephalopathy, retinopathy and hearing loss. We report a new pediatric case, revealed by an occlusive retinal arteritis.

A 12-year-old girl presented to the emergency room because of sudden onset of photopsias in her right temporal visual field. One year previously, she had developed an acute disseminated encephalomyelitis, resolving with steroids. Visual acuity was 10/10-P2 in both eyes. Fundus examination revealed a thin right inferior nasal artery. Fluorescein angiography revealed an occlusion of this artery and occlusive peripheral arterial vasculitis. An IV steroid bolus was administered urgently. Brain MRI showed high signal intensity abnormalities in the corpus callosum. The clinical triad was rapidly completed by a bilateral hearing loss. Intravenous immunoglobulins were initiated. The occurrence of contralateral occlusive retinal arteritis two months later led to treatment with cyclophosphamide. After 6 infusions, visual acuity was stable, but the visual field remained, and regression of the vasculitis remained incomplete.

Three hundred cases of SS have been reported with predominance in young women. Pediatric cases are rare. Diagnosis is difficult, because the typical clinical triad is often incomplete. Occurrence of relapses is unpredictable. Visual prognosis depends on the location of the occluded retinal territories. Treatment, based on a combination of steroids, immunosuppressive and antiplatelet agents is not always able to prevent relapse, as in our case.

Unpredictable progression of SS requires early diagnosis and treatment as well as close monitoring. It must always be considered in the case of any occlusive retinal arteritis, even in children.