Frosted branch angiitis as a rare manifestation of systemic Bartonella infection

An 11-year-old boy presented with seizures and sudden bilateral vision loss. Brain magnetic resonance imaging suggested central nervous system (CNS) vasculitis. Fundus examination revealed frosted branch angiitis, optic disc edema, vitritis, and patches of retinitis in both eyes. Initial treatment with valacyclovir for suspected acute retinal necrosis was ineffective, and vision worsened despite pulse steroid therapy. Further evaluation for infectious causes showed positive IgM titers for Bartonella species. Systemic treatment with doxycycline and rifampicin resulted in significant clinical improvement. This case highlights the unusual presentation of cat scratch disease, manifesting as frosted branch angiitis and CNS vasculitis.