Frosted branched angiitis due to viral meningo-encephalitis and ocular toxoplasmosis; a rare case report from Nepal

Frosted branched angiitis (FBA) is characteristic florid translucent retinal perivascular sheathing of both arterioles and venules in association with variable uveitis and vasculitis affecting the entire retina. The vascular sheathing is supposed to be an immune-mediated reaction, possibly due to immune complex deposition in vessel walls secondary to various underlying etiologies. The authors aim to report a case of FBA secondary to herpes simplex virus and Toxoplasma gondii infection causing the diagnostic dilemma. This is the first case report on FBA from Nepal. CASE REPORT: An 18-year-old young boy hospitalized with the diagnosis of acute viral meningo-encephalitis presented with the complaint of diminution of vision and floaters in both eyes for a week. Herpetic infection was confirmed with the cerebro-spinal fluid analysis and was under antiviral drugs. His presenting visual acuity was 20/80 in both eyes and ocular features were suggestive of FBA. The vitreous sample analysis revealed raised toxoplasma titre so intravitreal clindamycin was administered twice. The ocular features resolved in the subsequent follow ups with intravenous antiviral treatment and intravitreal antitoxoplasma treatment. CONCLUSIONS: FBA is a very rare clinical syndrome secondary to many immunological or pathological causes. So, possible etiologies must be ruled out for timely management and good visual prognosis.