Much-Ado About Acute Vision Loss

He was initially diagnosed with ischemic optic neuropathy and left eye vascular occlusions. However, fluorescein angiography (FA) revealed normal filling and transit times, inconsistent with retinal or choroidal vascular occlusions. Given these results, the disc edema was deemed secondary to an infiltrative neuropathy causing secondary ischemia with resultant multi-layered hemorrhages. Laboratory work-up revealed pancytopenia with negative HIV testing, hepatitis panel, Mycoplasma titer, Treponema antibody, cANCA, pANCA, CCP and dsDNA. The initial differential diagnosis included post-infectious or drug-induced hypersensitivity and hemophagocytic lymphohistiocytosis (HLH). Hematology ruled out HLH based on diagnostic criteria and review of peripheral blood smears.1-5 Repeat MRI brain revealed multiple hyper-intense cortical and subcortical white matter lesions concerning for emboli or meningoencephalitis, but lumbar puncture had normal opening pressure and was negative for infection. A diagnostic skin biopsy was then performed, revealing interface dermatitis with superficial and perivascular lymphocytic infiltrate without evidence of vasculitis, viral cytopathic changes, or tumor, consistent with pityriasis lichenoides et varioliformis acuta (PLEVA) or ulceronecrotic Mucha-Habermann disease versus erythema multiforme. A rare acquired dermatitis also thought to be a post-infectious immune system derangement, PLEVA is characterized by erythematous scaly papules with hemorrhagic, papulonecrotic lesions, CNS changes, high fevers, interstitial pneumonitis, pancytopenia, and diffuse intravascular coagulation.6-8 The patient improved on a one-week course of intravenous methylprednisolone, and was discharged home on oral prednisone, currently transitioning to methotrexate maintenance therapy. His right eye vision improved to 20/40 and final MRI revealed interval resolution of all hyper-intense lesions.